Question 1

Choose the pair of missing terms from the given alternatives that will correctly complete the letter series T, R, P, N, L, ?, ?

Accepted Answer

Introduction / Context: This problem involves a letter series where alphabets appear in a particular order and two terms are missing at the end. The aim is to identify the underlying pattern in the positions of the letters and then extend that pattern logically. Such questions test familiarity with the alphabetical order, the ability to map letters to their numerical positions, and the skill to recognize constant or regular changes between these positions. These are common in verbal reasoning sections of competitive exams. Given Data / Assumptions: The letter series is T, R, P, N, L, ?, ?. We must find two missing letters that complete the pattern. All letters are from the English alphabet and are considered in standard alphabetical order. The rule should apply consistently from the first term to the last term. Concept / Approach: The key concept is to convert letters into their alphabet positions and analyze the numerical pattern. For the English alphabet, A is 1, B is 2, C is 3 and so on up to Z as 26. Once we identify how much each letter moves forward or backward in terms of positions, we can replicate that same shift to find the missing letters. In many letter series questions, the difference between successive letters remains constant or follows a simple arithmetic rule like plus two or minus three. Step-by-Step Solution: Step 1: Convert letters to their numerical positions: T = 20, R = 18, P = 16, N = 14, L = 12. Step 2: Examine the differences between consecutive positions: 20 to 18 is minus 2, 18 to 16 is minus 2, 16 to 14 is minus 2, 14 to 12 is minus 2. Step 3: The pattern is a constant backward movement of 2 positions in the alphabet. Step 4: Apply the same rule to L, which is 12: 12 minus 2 gives 10, corresponding to J. Step 5: Continue once more: 10 minus 2 gives 8, corresponding to H. Thus the missing pair is J, H. Verification / Alternative check: Reconstruct the entire sequence with the found letters: T (20), R (18), P (16), N (14), L (12), J (10), H (8). Now check every step: 20 to 18 (minus 2), 18 to 16 (minus 2), 16 to 14 (minus 2), 14 to 12 (minus 2), 12 to 10 (minus 2), 10 to 8 (minus 2). The constant difference of minus 2 is preserved for the complete series, confirming that J and H are the correct missing letters. Why Other Options Are Wrong: Option A (K, I) corresponds to positions 11 and 9, which would give transitions 12 to 11 and 11 to 9, breaking the minus 2 regularity. Option C (J, G) yields 12 to 10 (correct) but then 10 to 7 (minus 3) which violates the rule. Option D (K, H) produces mixed differences of minus 1 and minus 3. Option E (L, J) simply repeats L and then moves to J, so the step from N to L to L again does not maintain the consistent minus 2 pattern. Only J, H maintains the same change throughout. Common Pitfalls: One frequent mistake is to look for alternating patterns or to guess randomly based on partial similarity without converting letters to numbers. Another pitfall is to miscalculate alphabetical positions, for example confusing the position of J, K, or L, which then leads to wrong differences. Some learners also forget to verify the pattern for all transitions and only check a portion of the series. Careful step wise verification helps avoid these errors. Final Answer: The pair of letters that correctly completes the series with a constant backward step of two positions is J, H.

Question 2

Choose the missing term from the given alternatives that will correctly complete the letter series ejo, tyd, ins, xch, ?

Accepted Answer

Introduction / Context: This is a non standard letter series where each term is a three letter group. The relationship from one group to the next is not immediately obvious, so the problem tests deeper pattern recognition in the positions of letters. Instead of a simple forward or backward shift, each position within the group follows its own rule. Such questions are useful for checking how well a candidate can track multiple patterns simultaneously across different positions in a letter block. Given Data / Assumptions: The given series of three letter groups is ejo, tyd, ins, xch, ?. We must determine the next three letter group that continues all observed patterns. All letters are from the English alphabet and follow the usual A to Z order. Each of the three positions within the group may have its own independent sequence. Concept / Approach: The best approach is to treat each position first letter, second letter, and third letter as separate series. For each position, we convert letters to their numerical positions (A as 1, B as 2, and so on) and then inspect the pattern. Often such series feature alternating additions and subtractions by fixed numbers. Once we find a consistent rule for each of the three independent sequences, we can compute the next letter for every position and combine them to form the missing term. Step-by-Step Solution: Step 1: First letters: e, t, i, x correspond to 5, 20, 9, 24. Step 2: Observe differences: 5 to 20 is plus 15, 20 to 9 is minus 11, 9 to 24 is plus 15. So the pattern alternates between plus 15 and minus 11, so the next step should be 24 minus 11 = 13, which is m. Step 3: Second letters: j, y, n, c correspond to 10, 25, 14, 3. Here too the pattern alternates: plus 15, minus 11, plus 15, so the next should be 3 minus 11. Using the 26 letter cycle, 3 minus 11 gives 18 which is r. Step 4: Third letters: o, d, s, h correspond to 15, 4, 19, 8. Now the pattern is minus 11, plus 15, minus 11, so the next step is plus 15 from 8, yielding 23 which is w. Step 5: Combine the results from each position: first letter m, second letter r, third letter w, giving the group mrw. Verification / Alternative check: Write out the numerical positions clearly to verify. First position: 5, 20, 9, 24, 13 with pattern plus 15, minus 11, plus 15, minus 11. Second position: 10, 25, 14, 3, 18 with the same alternation. Third position: 15, 4, 19, 8, 23 also follows minus 11, plus 15, minus 11, plus 15. In each case, the rule is a consistent alternation of adding 15 and subtracting 11 in the 1 to 26 modular alphabet. The resulting group mrw therefore fits all three position wise rules perfectly. Why Other Options Are Wrong: Option nrw changes the first letter from m to n, breaking the strict plus 15, minus 11 cycle for the first position. Option nsx alters both the second and third letters, making the internal differences inconsistent with the earlier transitions. Option nsw again fails to match the exact required numerical shifts. Option mqw changes the second and third letters to q and w, which no longer respect the alternating plus 15 and minus 11 pattern. Only mrw preserves the required arithmetic behavior at every position. Common Pitfalls: Candidates often look for one single rule across whole groups, such as rotation or reversal, without decomposing the pattern by position. Another common mistake is to work only with letters, not converting them to numbers, which makes it harder to track consistent differences like plus 15 or minus 11. Some learners also apply the wrong modulo logic when subtracting, forgetting that after going below A you should wrap around to the end of the alphabet. Careful numerical treatment of each position avoids these errors. Final Answer: The three letter group that correctly continues the alternating positional pattern is mrw.

Question 3

In the following letter series, some letters are missing and are shown as blanks. The missing letters occur in the same left to right order as in one of the options. Choose the option that correctly completes the series ba_ba_bac_acb_cbac.

Accepted Answer

Introduction / Context: This letter series question hides a repeating pattern and uses blanks to break the visible repetition. The task is to fill the blanks with letters in such a way that the entire series becomes a smooth repetition of a smaller block of letters. Such problems test the ability to detect repeating units and to associate the order of missing letters in the main series with the order of letters in the answer options. This is a common type of question in verbal reasoning and logical ability examinations. Given Data / Assumptions: The incomplete series is written as ba_ba_bac_acb_cbac. Blanks represent missing letters that must be placed in the order given by one of the options. Each option is a four letter string, and these four letters replace the blanks in sequence from left to right. The completed series should exhibit a clear and consistent pattern, ideally a simple repetition. Concept / Approach: The natural strategy is to consider that the series might be composed of a repeated block such as bac. We can attempt to fill the blanks with the letters from each option and then inspect the final string. The correct option should transform the messy looking series into something that showcases a neat repetition or easily describable order. Rather than relying on intuition alone, we systematically test each option by substitution and see whether a recognizable repeating group emerges. Step-by-Step Solution: Step 1: Represent the pattern with underscores as ba_ba_bac_acb_cbac, where there are four blanks. Step 2: Take option ccba and substitute its letters into the blanks in order: first c, second c, third b, fourth a. Step 3: After substitution, the string becomes bacbacbacbacbacbac, which is bac repeated six times. Step 4: Observe that bac is a three letter block, and the entire completed series consists solely of this block in perfect repetition. Step 5: This level of regularity strongly indicates that option ccba is the intended choice. Verification / Alternative check: To verify, we can also test the other options briefly. Substituting bbca, cbac, aacb, or bcca does not produce a simple uniform repetition. Their completed strings contain irregular segments and do not reduce to consistent repeated units. Only when we use ccba do we obtain bacbacbacbacbacbac with no deviations. That is a very strong confirmation, as exam questions of this type are designed around clear and elegant patterns like exact repetition of a small group. Why Other Options Are Wrong: Option bbca leads to a complex mixture that does not display any simple repeating unit. Option cbac also fails to generate a recognizably repeated three letter pattern across the entire string. Option aacb similarly produces a fragmented sequence instead of a neat repetition. Option bcca has no interpretation that yields a consistent repeated block. Because exam series questions aim for concise underlying structures, these irregular outcomes are not acceptable. Therefore, none of these options matches the elegant bac repetition that we get from ccba. Common Pitfalls: Students sometimes try to analyze the series purely from left to right without considering that a smaller repeating block may lie beneath the surface. Another common mistake is to stop after checking only the first few letters after substitution, rather than confirming that the entire completed sequence follows the same pattern. Some learners also rely on visual similarity instead of actually writing out the full string, which can hide inconsistencies. A careful and complete substitution check prevents these errors. Final Answer: The only option that converts the series into a clean repetition of the block bac is ccba, so that is the correct set of missing letters.

Question 4

Find the missing number in the following series: 2, 3, 10, 39, ?, 885.

Accepted Answer

Introduction / Context: This is a number series problem where the terms grow rapidly, suggesting a combination of multiplication and addition. Such questions are intended to test a deeper understanding of series in which each term is generated from the previous one using both multiplication and an additional term that itself follows a pattern. Recognizing this two level structure is essential for many aptitude exams involving complex numerical reasoning. Given Data / Assumptions: The series is 2, 3, 10, 39, ?, 885. We need to find a single missing term between 39 and 885. The numbers increase quickly, hinting at repeated multiplication by a variable factor. There is likely a secondary pattern in the additive component, such as squares or cubes of integers. Concept / Approach: When growth is fast but not purely exponential, a common pattern is a mix of multiplication and addition. Specifically, many exam series follow a rule like a(n+1) = a(n) * k(n) + extra(n), where k(n) and extra(n) follow simple sequences. A good starting point is to try multiplying each term by small integers and then checking the gap between the product and the next term. If those gaps form a recognizable pattern, such as consecutive squares, we can generalize the rule and compute the missing term accordingly. Step-by-Step Solution: Step 1: From 2 to 3: 2 * 1 = 2 and 2 + 1 = 3, so effectively 2 * 1 + 1 = 3. Step 2: From 3 to 10: 3 * 2 = 6 and 6 + 4 = 10, so 3 * 2 + 4 = 10. Step 3: From 10 to 39: 10 * 3 = 30 and 30 + 9 = 39, so 10 * 3 + 9 = 39. Step 4: Notice that the added numbers 1, 4, 9 are 1^2, 2^2, 3^2 respectively. Step 5: Continue the pattern: next step should be 39 * 4 + 4^2 = 39 * 4 + 16 = 156 + 16 = 172, and then 172 * 5 + 5^2 = 172 * 5 + 25 = 860 + 25 = 885, which matches the last term. Verification / Alternative check: Check each transition with the rule a(n+1) = a(n) * n + n^2 starting from n = 1. For n = 1: 2 * 1 + 1^2 = 3. For n = 2: 3 * 2 + 2^2 = 10. For n = 3: 10 * 3 + 3^2 = 39. For n = 4: 39 * 4 + 4^2 = 172. For n = 5: 172 * 5 + 5^2 = 885. Every step fits perfectly, including the given final term 885, which confirms that 172 is the only consistent missing value. Why Other Options Are Wrong: Option 128, when used as the missing term, fails because 128 * 5 + 25 equals 665, not 885, breaking the sequence. Option 156 leads to 156 * 5 + 25 = 805, which does not match. Option 189 produces 189 * 5 + 25 = 970, again inconsistent. Option 164 gives 164 * 5 + 25 = 845, still not equal to 885. None of these maintain the rule of multiplication by increasing integers plus perfect squares, so they must be rejected. Common Pitfalls: Many learners initially look only at differences between terms, which in this case are 1, 7, 29, and then some unknown gap, and do not see a simple pattern. Others might attempt fixed multiplication factors without considering an additive part. A further trap is to guess the missing term using approximate growth rather than exact rules. The safe strategy is to check for multiplying by 1, 2, 3, 4 and adding 1^2, 2^2, 3^2, 4^2, which is a familiar exam pattern that often appears in high level reasoning questions. Final Answer: The missing number that follows the rule a(n+1) = a(n) * n + n^2 and leads correctly to 885 is 172.

Question 5

Find the wrong term in the number series 1, 5, 9, 15, 25, 37, 49.

Accepted Answer

Introduction / Context: This question asks you to detect the incorrect term in an otherwise regular number series. Instead of filling a missing value, you must identify which given value breaks the pattern. Such problems are very common in reasoning tests because they require not only seeing the rule that generates the series but also checking every term against that rule to see which one does not fit. Given Data / Assumptions: The series provided is 1, 5, 9, 15, 25, 37, 49. Exactly one of these terms is wrong; the rest form a consistent pattern. The pattern likely relates to differences between consecutive terms. We must find the offending term that does not conform to the common rule. Concept / Approach: For wrong term questions, it is usually easier to first assume that the series is correct and try to deduce a rule. If that rule works for most transitions but fails at a particular value, that value is the wrong term. Here, the numbers increase moderately, suggesting that the series might be based on adding numbers that themselves follow a pattern, such as in pairs or groups. Recognizing repetition in the differences can reveal the intended structure, and any deviation immediately highlights the incorrect term. Step-by-Step Solution: Step 1: Compute differences between terms: 1 to 5 is plus 4, 5 to 9 is plus 4, 9 to 15 is plus 6, 15 to 25 is plus 10, 25 to 37 is plus 12, 37 to 49 is plus 12. Step 2: The differences are 4, 4, 6, 10, 12, 12. Step 3: A reasonable intended pattern is to have equal differences in pairs that themselves increase: plus 4, plus 4, plus 8, plus 8, plus 12, plus 12. Step 4: Based on this intended rule, the correct sequence would be 1, 5, 9, 17, 25, 37, 49, where after adding 4 twice, we add 8 twice, then 12 twice. Step 5: Comparing the intended correct sequence with the given one, only the third term after 9 is different: the series has 15 instead of 17, so 15 must be the wrong term. Verification / Alternative check: Reconstruct the ideal series using the rule of equal differences in pairs. Start from 1: add 4 to get 5, add 4 to get 9. Then add 8 to get 17, add 8 to get 25. Next add 12 to get 37, add 12 to get 49. The fully consistent series is therefore 1, 5, 9, 17, 25, 37, 49. In this correct pattern, every pair of successive differences is equal and then increases by 4 for the next pair. The given series matches this pattern at all positions except at 15, confirming that 15 is the misplaced term. Why Other Options Are Wrong: Term 49 fits because the last difference from 37 to 49 is 12, matching the second 12 in the final pair. Term 37 is also correct because 25 to 37 is 12, the start of that pair. Term 25 fits as the second number after adding 8 twice. Term 9 fits the initial pair of plus 4 differences. None of these break the systematic pairwise pattern in the differences. Only 15 results in an irregular jump and destroys the pairwise structure of the series. Common Pitfalls: Students may try to fit a more complicated pattern involving squares or cubes, which is unnecessary in this case. Another common mistake is to focus on small parts of the series and ignore the overall pair structure in the differences. Some learners also assume that the incorrect term is likely at the end or beginning of the sequence without checking every transition. A disciplined approach is to compute all consecutive differences and look for neat groupings or repeating units; any violation typically indicates the wrong term. Final Answer: The term that violates the pattern of differences grouped in equal pairs is 15, so 15 is the wrong term in the series.

Question 6

What will come in place of the question mark in the following number series: 5, 14, 45, 130, ?, 1182?

Accepted Answer

Introduction / Context: This number series problem features rapidly increasing values where the pattern is not simply multiplication by a fixed factor. Instead, a combination of multiplication and addition or subtraction is involved, with the additive part following its own structure. Such series are designed to measure a candidate ability to handle multi layer patterns, where both the multiplicative factor and the additive or subtractive term change in a controlled way across the sequence. Given Data / Assumptions: The series is 5, 14, 45, 130, ?, 1182. One term between 130 and 1182 is missing. The growth between terms is steep, suggesting repeated multiplication by a similar factor, with extra adjustments. The adjustments are likely to be systematically increasing odd numbers with alternating signs. Concept / Approach: A common pattern in advanced series involves multiplying by a constant factor, such as 3, and then adding or subtracting successive odd numbers. Here, we suspect a rule like a(n+1) = 3 * a(n) + or minus some odd number following a simple pattern. We must check each step, determine the sequence of these odd numbers, and see how they are combined with multiplication by 3. Once that is identified, we can compute the missing term and verify that the subsequent given term also fits the same rule. Step-by-Step Solution: Step 1: From 5 to 14: 5 * 3 = 15; to get 14 we subtract 1, so 5 * 3 - 1 = 14. Step 2: From 14 to 45: 14 * 3 = 42; to get 45 we add 3, so 14 * 3 + 3 = 45. Step 3: From 45 to 130: 45 * 3 = 135; to get 130 we subtract 5, so 45 * 3 - 5 = 130. Step 4: The adjustment terms are -1, +3, -5, which are odd numbers with alternating signs and increasing magnitude. The next adjustment should be +7. Step 5: Therefore, the missing term after 130 is 130 * 3 + 7 = 390 + 7 = 397. For verification, 397 * 3 = 1191, and the next adjustment must be -9, giving 1191 - 9 = 1182, which matches the given last term. Verification / Alternative check: Summarize the rule as a(n+1) = 3 * a(n) + k(n), with k(n) being -1, +3, -5, +7, -9 and so on, that is alternating signs with odd numbers in ascending order. Check each step: 5 * 3 - 1 = 14, 14 * 3 + 3 = 45, 45 * 3 - 5 = 130, 130 * 3 + 7 = 397, 397 * 3 - 9 = 1182. All transitions match both the multiplicative factor 3 and the odd number adjustment sequence, so the pattern is internally consistent and confirms 397 as the correct missing term. Why Other Options Are Wrong: Option 222 does not work because 130 * 3 plus or minus any single odd number cannot produce 222, and 222 * 3 plus or minus an odd number will not yield 1182. Option 404 also fails both from 130 and towards 1182. Option 415 does not fit, since 130 * 3 is 390, and adding odd numbers 1, 3, 5, 7, 9 cannot give 415 without breaking the alternating sign rule. Option 350 similarly cannot be reconciled with the established sequence of adjustments. Only 397 satisfies both transitions, from 130 and to 1182, under the same rule. Common Pitfalls: Learners often attempt to look at simple differences between terms in such non linear series, but the differences 9, 31, 85, and so on appear quite irregular. Another error is to guess that the series is purely geometric, which does not hold here because the ratio between terms is not constant. Some students also miss the alternating sign pattern in the adjustments and treat them as random. Recognizing the repeated factor 3 and then focusing on the sequence of odd numbers is the key to solving this efficiently. Final Answer: The number that correctly completes the pattern of multiplying by 3 and adding or subtracting successive odd numbers is 397.

Question 7

Find the next number in the series 18, 90, 450, 2250, ?

Accepted Answer

Introduction / Context: This is a classic geometric style number series, where each term is obtained by multiplying the previous one by a constant factor. Such questions are fundamental in aptitude tests because they require recognition of simple multiplicative relationships. Once the common ratio is detected, predicting the next term is straightforward and involves only basic multiplication. Given Data / Assumptions: The series given is 18, 90, 450, 2250, ?. We must find the single missing term that follows 2250. The numbers increase at a uniform multiplicative rate. There is no additional addition or subtraction term; the pattern is purely multiplicative. Concept / Approach: In geometric series questions, the central idea is the common ratio. We divide each term by its predecessor to see if the resulting ratio is constant. If the same ratio appears consistently, the series is geometric with that ratio. We then multiply the last known term by this ratio to obtain the next term. The steps are short and mechanical once the ratio is identified, making this type of question very scoring for well prepared candidates. Step-by-Step Solution: Step 1: Compute the ratio of the second term to the first: 90 / 18 = 5. Step 2: Compute the ratio of the third term to the second: 450 / 90 = 5, which matches the previous ratio. Step 3: Compute the ratio of the fourth term to the third: 2250 / 450 = 5, confirming a constant ratio of 5 throughout. Step 4: Since the series is geometric with common ratio 5, the next term is 2250 * 5. Step 5: Calculate 2250 * 5 = 11250. This is the required next term. Verification / Alternative check: Write the series explicitly with the ratio: 18, 18 * 5 = 90, 90 * 5 = 450, 450 * 5 = 2250, 2250 * 5 = 11250. Each step involves a clean multiplication by 5 with no extra modification. There are no deviations from this rule, and using 11250 as the next term keeps the series perfectly consistent. Any different value would create a break in the otherwise flawless geometric pattern. Why Other Options Are Wrong: Option 4520 is almost twice 2250, but the ratio 4520 / 2250 is not equal to 5 and fails the geometric rule. Option 6520 similarly gives a ratio that does not equal 5. Option 7250 also fails the constant ratio test, as 7250 / 2250 is not 5. Option 9000, though large, yields a ratio of 4, which contradicts the clearly established ratio of 5 among the earlier terms. None of these alternatives respect the simple multiply by 5 pattern. Common Pitfalls: Some students are tempted to look at differences between terms, but in geometric series the differences typically grow irregularly, which can be misleading. Others may mentally approximate the ratio and choose a nearby value instead of calculating precisely. Another error is to see large numbers and assume a more complex rule than necessary. The key is to always start by checking the ratio between consecutive terms for potential geometric behavior, especially when the jumps are large and regular looking as in this example. Final Answer: The next term in the geometric series with common ratio 5 is 11250.

Question 8

Find the next term in the series 3, 6, 17.5, 64.75, ?

Accepted Answer

Introduction / Context: This question presents a non standard number series with decimal values and rapidly increasing terms. Such series are meant to test advanced pattern recognition, particularly when both the multiplicative factor and an additive constant appear to change together. Candidates must be comfortable working with fractional multipliers and decimals, and must systematically test possible rules instead of guessing by rough magnitude alone. Given Data / Assumptions: The series is 3, 6, 17.5, 64.75, ?. We must find the next term in the sequence. All terms after the first are larger than their predecessors, and decimals appear from the third term onward. The pattern likely involves multiplication by gradually increasing factors along with a related additive component. Concept / Approach: Rather than looking at simple differences, which are irregular here, it is more effective to see how each term can be expressed as the previous term multiplied by a factor and then adjusted by a constant. A closely related pattern is that each step multiplies by n point five and adds the same n point five, where n increases by one each time. This structure, multiply then add by the same half integer, explains the decimal nature of the series and provides a consistent way to compute subsequent terms. Step-by-Step Solution: Step 1: From 3 to 6: 3 * 1.5 + 1.5 = 4.5 + 1.5 = 6, so the factor and addition are both 1.5. Step 2: From 6 to 17.5: 6 * 2.5 + 2.5 = 15 + 2.5 = 17.5, with factor and addition both 2.5. Step 3: From 17.5 to 64.75: 17.5 * 3.5 + 3.5 = 61.25 + 3.5 = 64.75, with factor and addition both 3.5. Step 4: The pattern is clear: at each step we multiply by (n + 0.5) and then add (n + 0.5), where n takes values 1, 2, 3, and so on. Step 5: For the next term, use n = 4, so factor and addition are 4.5. Compute 64.75 * 4.5 + 4.5 = 291.375 + 4.5 = 295.875. Verification / Alternative check: We can rewrite each term using the pattern a(n+1) = a(n) * (n + 0.5) + (n + 0.5). With a(1) = 3, we get a(2) = 3 * 1.5 + 1.5 = 6, a(3) = 6 * 2.5 + 2.5 = 17.5, a(4) = 17.5 * 3.5 + 3.5 = 64.75, a(5) = 64.75 * 4.5 + 4.5 = 295.875. Every term matches the provided series up to the fourth one, and the calculation for the fifth term smoothly extends the same rule. No other candidate value yields such a perfect continuation with this consistent structure. Why Other Options Are Wrong: Option 304.587 cannot be formed by multiplying 64.75 by any half integer of the observed type and then adding the same value. Option 115.246 is far too small relative to the established growth and does not match any logical factor plus the same addend. Option 101 similarly fails, as 64.75 multiplied by a factor around 1.5 or 2.5 would not align with earlier steps. Option 250.375 also breaks the clear pattern of using factors 1.5, 2.5, 3.5, 4.5 and adding the same half integer. Only 295.875 is generated exactly from 64.75 using factor and addition 4.5. Common Pitfalls: Many candidates first attempt to use constant or integer ratios, which quickly fail because the ratios between terms here are not integers. Others look purely at differences, but the successive differences do not follow a simple progression. Some learners hesitate when decimals appear and assume a very complicated or arbitrary rule. Recognizing that half integer multipliers, such as 1.5, 2.5, 3.5, are natural extensions of integer patterns enables a clean solution. Practicing such mixed integer and decimal series improves confidence with these question types. Final Answer: The next term in the series, obtained by multiplying 64.75 by 4.5 and adding 4.5, is 295.875.

Question 9

Choose the missing term from the given alternatives that will correctly complete the series ADVENTURE, DVENTURE, DVENTUR, ?, VENTU.

Accepted Answer

Introduction / Context: This is a word series question built from the single base word ADVENTURE. Parts of the word are gradually removed in a systematic way to form each subsequent term in the series. Such problems test a candidate ability to track letter removal from the beginning and end of a word and to infer the next logically shortened form. These questions rely more on pattern observation than on complex language knowledge. Given Data / Assumptions: The series is ADVENTURE, DVENTURE, DVENTUR, ?, VENTU. All terms are derived from the base word ADVENTURE. At each step, one letter appears to be removed from either the start or the end. We must find the unique intermediate form that continues this removal pattern. Concept / Approach: The key idea is to compare each term with its predecessor and examine which letter has been removed. If we see a consistent alternation between removing the first and the last letter, we can predict the next step. The process is like trimming the word from alternating ends, which produces a nested sequence. Recognizing this alternation helps us determine exactly which letters remain at each stage, including the missing term. Step-by-Step Solution: Step 1: Start with ADVENTURE. Step 2: The second term is DVENTURE, which is obtained by removing the first letter A from ADVENTURE. Step 3: The third term is DVENTUR, which is obtained from DVENTURE by removing the last letter E. Step 4: Following the alternation of removing from the front and then from the back, the next step should remove the first letter D from DVENTUR, leaving VENTUR. Step 5: The given last term is VENTU, which is obtained by removing the final letter R from VENTUR, confirming that the pattern continues correctly. Verification / Alternative check: List the transformations clearly: ADVENTURE minus first letter A becomes DVENTURE. DVENTURE minus last letter E becomes DVENTUR. DVENTUR minus first letter D becomes VENTUR. VENTUR minus last letter R becomes VENTU. The process is therefore: remove from front, remove from back, remove from front, remove from back, and so on. The missing word between DVENTUR and VENTU must be the form that appears after removing from the front but before removing from the back again, which is VENTUR. This confirms the pattern and the answer. Why Other Options Are Wrong: Option VENTURE reintroduces letters that were already removed and breaks the monotonic shrinkage of the word. Option DVENT still begins with D but is shorter than DVENTUR in an incorrect way and does not match the alternating front back removal rule. Option DVENTU also deviate from the simple front or back removal pattern by effectively removing letters from the middle. Option AVENTUR adds the letter A at the front, reversing part of the earlier removal. None of these match the strict alternate trimming rule that the series demonstrates. Common Pitfalls: Some students miscount letters or assume multiple letters are removed at each step, leading to complicated interpretations. Others overlook the alternation and think letters are always removed from the same side. Another error is to focus on the meaning of the word rather than on its spelling structure. It is essential to concentrate only on which characters are lost from one term to the next and to track that process consistently across the entire series. Final Answer: The missing word that continues the alternation of removing letters from the front and back is VENTUR.

Question 10

In the number series 2, 4, 12, 48, 240, decide whether the last term 240 correctly continues the pattern of the previous terms.

Accepted Answer

Introduction / Context: This question is slightly different from typical missing term problems. Instead of asking for a new number, it asks us to validate whether the last term in the series is consistent with the established pattern. Such validation questions test both the ability to infer a rule and the capacity to check that a given term satisfies that rule without assuming it is always correct. Given Data / Assumptions: The series is 2, 4, 12, 48, 240. We must decide if 240 is the correct term that follows from 2, 4, 12, and 48. The numbers grow quickly, suggesting a multiplicative pattern. We assume that there is a simple, uniform rule generating each new term from the previous one. Concept / Approach: To validate the last term, we must first uncover the governing rule from the earlier part of the series and then see if that same rule transforms 48 into 240. The pattern appears to involve multiplying each term by an increasing integer factor. By carefully examining these factors between each pair of terms, we can determine if 240 is the correct result of applying the next factor in the sequence to 48. Step-by-Step Solution: Step 1: From 2 to 4, the multiplier is 2 since 2 * 2 = 4. Step 2: From 4 to 12, the multiplier is 3 since 4 * 3 = 12. Step 3: From 12 to 48, the multiplier is 4 since 12 * 4 = 48. Step 4: These multipliers form the sequence 2, 3, 4, which suggests that the next multiplier should be 5. Step 5: Apply this multiplier to 48: 48 * 5 = 240, which matches the given last term. Verification / Alternative check: If we write the series using the rule explicitly, we have 2, 2 * 2 = 4, 4 * 3 = 12, 12 * 4 = 48, 48 * 5 = 240. The factors 2, 3, 4, 5 are consecutive integers, and there is no irregularity in the pattern. Therefore, 240 is exactly the number we would derive from applying the rule, and there is no reason to doubt its correctness. If 240 were wrong, it would not be obtainable from 48 by multiplying with the next integer in this obvious factor sequence. Why Other Options Are Wrong: The option that claims the series is incorrect cannot be accepted, because we have found a clear and simple pattern that fits every term. The options stating that the pattern cannot be determined or that there is no consistent pattern ignore the straightforward use of successive integer multipliers. The suggestion that some other value should replace 240 is also invalid, because replacing 240 with another number would break the neat rule of multipliers 2, 3, 4, 5. Common Pitfalls: Some learners may overthink and look for more complex rules, such as combinations of addition and multiplication, when a direct pattern in the multipliers is sufficient. Others may prematurely judge the last term as suspicious simply because it is large. It is important to systematically examine each pair of consecutive terms and confirm whether the multiplier pattern is stable and logical before deciding on correctness. Final Answer: The last term 240 is indeed produced by multiplying 48 by 5, so the correct conclusion is Correct, it follows the pattern.

Question 11

Find the missing number in the series 15, 51, 216, 1100, ?, 46452.

Accepted Answer

Introduction / Context: This number series grows very rapidly and is constructed from a more sophisticated rule that combines multiplication with an additive term that is itself structured. The problem checks higher level numerical reasoning and the ability to detect patterns that incorporate both the position of the term and its value. Such questions often appear in more challenging sections of reasoning tests. Given Data / Assumptions: The given series is 15, 51, 216, 1100, ?, 46452. One number between 1100 and 46452 is missing. The progression appears to involve multiplying by increasing integers. There is also an added term that depends on the same integer used for multiplication. Concept / Approach: A natural strategy is to test whether a(n+1) can be expressed as a(n) multiplied by a small integer plus some structured additive term. Examining the first few transitions can reveal how both the multiplier and the addition depend on the step number. Here, we find that the multiplier grows in a simple linear way, and the additive term is the product of two consecutive integers. Once we find a general rule that matches all known transitions, we can apply it to calculate the missing term and confirm it by checking the final transition to 46452. Step-by-Step Solution: Step 1: From 15 to 51: 15 * 3 = 45, and 45 + 6 = 51; note that 6 = 3 * 2. Step 2: From 51 to 216: 51 * 4 = 204, and 204 + 12 = 216; note that 12 = 4 * 3. Step 3: From 216 to 1100: 216 * 5 = 1080, and 1080 + 20 = 1100; note that 20 = 5 * 4. Step 4: The pattern is: a(n+1) = a(n) * k + k * (k - 1), where k takes values 3, 4, 5 and increases by 1 each time. Step 5: For the next step, k = 6, so the missing term is a(5) = 1100 * 6 + 6 * 5 = 6600 + 30 = 6630. Then with k = 7, compute 6630 * 7 + 7 * 6 = 46410 + 42 = 46452, matching the given last term. Verification / Alternative check: We can describe the rule generically as a(n+1) = a(n) * (n + 2) + (n + 2) * (n + 1), starting from n = 1. Plugging in n = 1, we get 15 * 3 + 3 * 2 = 45 + 6 = 51. For n = 2, 51 * 4 + 4 * 3 = 204 + 12 = 216. For n = 3, 216 * 5 + 5 * 4 = 1080 + 20 = 1100. For n = 4, 1100 * 6 + 6 * 5 = 6600 + 30 = 6630. For n = 5, 6630 * 7 + 7 * 6 = 46410 + 42 = 46452. The rule holds at every step, confirming both the pattern and the missing value 6630. Why Other Options Are Wrong: Option 5660 would not satisfy the rule, because 5660 * 7 + 7 * 6 does not equal 46452. Option 6560 similarly fails when used in the formula. Option 6750 produces 6750 * 7 + 42 = 47292, which does not match the given final term. Option 6000 also does not lead to 46452 using the same pattern. Only 6630 simultaneously preserves the correct relationship with 1100 and yields 46452 when we apply the next step of the rule. Common Pitfalls: Many learners either ignore the additive term and search for pure multiplication, or they try to derive a pattern only from the differences. Both approaches fail because neither the ratios nor the differences alone follow a simple rule. Another mistake is to give up after matching only the first couple of transitions and not verifying the pattern against later terms. In high level series, confirming that the final given term also fits the same rule is crucial. Final Answer: The missing number that makes every transition conform to the rule a(n+1) = a(n) * k + k * (k - 1) is 6630.

Question 12

Find the wrong term in the number series 3, 4, 10, 32, 136, 685, 4116.

Accepted Answer

Introduction / Context: This question asks for the identification of the incorrect term in a rapidly growing number series. The series is built using a compound rule of multiplication and addition, and one term has been deliberately altered. The candidate must reverse engineer the intended rule and see which term does not comply. Such problems are useful for assessing the ability to spot a single inconsistency in an otherwise well structured pattern. Given Data / Assumptions: The given series is 3, 4, 10, 32, 136, 685, 4116. Exactly one term in this series is wrong. The correct series is generated by a uniform rule applied successively. The pattern likely involves multiplying by increasing integers and adding the same integer. Concept / Approach: A good starting point is to see whether each term can be produced from the previous one by multiplying with a certain integer and then adding that same integer. If this rule works for most transitions but fails at one point, the term at the failing point must be incorrect. In many exam series, factors increase by 1 each step, and the same increment is used for addition, leading to a rule of the type a(n+1) = a(n) * k + k. Step-by-Step Solution: Step 1: Test the rule from 3 to 4: 3 * 1 + 1 = 4; this fits the pattern multiply by 1 and add 1. Step 2: From 4 to 10: 4 * 2 + 2 = 8 + 2 = 10; now the factor and addition are both 2. Step 3: From 10 to 32: 10 * 3 + 3 = 33, but the series shows 32, so this term does not satisfy the rule. Step 4: From 10 using the intended rule, the correct next term should be 33, not 32. Step 5: Continue the correct series: 33 * 4 + 4 = 132 + 4 = 136, 136 * 5 + 5 = 680 + 5 = 685, 685 * 6 + 6 = 4110 + 6 = 4116, which all match the later terms. Verification / Alternative check: We can formalize the rule as a(n+1) = a(n) * (n) + (n) starting from a(1) = 3. Then a(2) = 3 * 1 + 1 = 4, a(3) = 4 * 2 + 2 = 10, a(4) = 10 * 3 + 3 = 33, a(5) = 33 * 4 + 4 = 136, a(6) = 136 * 5 + 5 = 685, a(7) = 685 * 6 + 6 = 4116. Every step except the one involving 32 is consistent with this formula. The presence of 32 instead of 33 at the fourth position is therefore the only deviation, naming 32 as the wrong term. Why Other Options Are Wrong: Term 136 is correct because it follows exactly from 33 under the rule multiply by 4 and add 4. Term 685 correctly results from 136 multiplied by 5 and then increased by 5. Term 4116 arises from 685 multiplied by 6 and increased by 6. Term 10 also correctly follows from 4. None of these violate the pattern. Only 32 cannot be obtained from 10 by multiplying by 3 and adding 3, so it alone is inconsistent with the intended rule. Common Pitfalls: Students often look at differences in such series, but the differences here are not simple and can be misleading. Others may notice only that numbers grow quickly and think the pattern is arbitrary. A further error is to assume that the wrong term must be near the end, whereas in many exam questions it is placed in the middle to force the candidate to check every transition. Carefully testing a consistent rule on each adjacent pair is the sure way to locate the incorrect term. Final Answer: The term that does not satisfy the rule a(n+1) = a(n) * n + n is 32, so 32 is the wrong term in the series.

Question 13

In the following question, pick out the most suitable substitute for the question mark: 6 : 222 :: 25 : ?

Accepted Answer

Introduction / Context: This is an analogy based numerical reasoning question. The relation between the first pair of numbers, 6 and 222, must be replicated for the second pair, 25 and the unknown value. Such questions are common in reasoning sections where the candidate must detect a mathematical relationship and then apply it consistently to a new number. Given Data / Assumptions: The analogy is written as 6 : 222 :: 25 : ?. The same mathematical operation that links 6 to 222 must link 25 to the required answer. The operation may involve powers, addition, or other standard arithmetic operations. Only one answer option will respect the exact relationship. Concept / Approach: A good way to approach such analogies is to try simple operations on the first number and see if they match the second. Since 222 is much larger than 6, exponentiation is a natural guess. We can test whether 222 can be expressed in terms of 6^2, 6^3, or similar, and then see what analogous operation on 25 produces one of the answer choices. In this case, the combination of cube and addition works elegantly and yields a neat rule. Step-by-Step Solution: Step 1: Compute 6^3 = 6 * 6 * 6 = 216. Step 2: Add 6 to this cube: 216 + 6 = 222. So 6 is mapped to 222 using the operation n^3 + n. Step 3: Apply the same operation to 25: compute 25^3. Step 4: 25^3 = 25 * 25 * 25 = 15625. Step 5: Add 25 to this result: 15625 + 25 = 15650. This must be the number that stands in the same relationship to 25 as 222 does to 6. Verification / Alternative check: We can express the mapping symbolically as f(n) = n^3 + n. Then f(6) = 6^3 + 6 = 216 + 6 = 222, which matches the given pair. For the second part, f(25) = 25^3 + 25 = 15625 + 25 = 15650. This exactly matches one of the answer options and preserves the same functional relationship. There is no simpler operation of similar elegance that maps 6 to 222 and also leads to one of the provided options when applied to 25. Why Other Options Are Wrong: Option 650 is far too small compared to 25^3 and does not arise from the operation n^3 + n. Option 15625 equals 25^3, but that would correspond to the rule n^3, which fails for the first pair since 6^3 is only 216, not 222. Option 15600 cannot be written as 25^3 plus or minus 25 in a neat way that keeps the relationship symmetrical. Option 3750 is also not consistent with the rule that 6 behaves as 6^3 plus itself. Therefore, only 15650 maintains the exact pattern n^3 + n. Common Pitfalls: Candidates sometimes focus on addition or multiplication alone and miss exponentiation, especially when the second number is significantly larger. Another mistake is to force unrelated operations for the two pairs instead of seeking one unifying rule. Some may stop after seeing that 15625 matches 25^3 and ignore the fact that 6^3 would then not match 222. Always confirm that the same function applied to both numbers in the first pair works for the second pair as well. Final Answer: The value that stands to 25 as 222 stands to 6 under the rule n^3 + n is 15650.

Question 14

Find the odd term out of the series 888, 440, 216, 104, 48, 22, 6.

Accepted Answer

Introduction / Context: This question presents a strictly decreasing number series and asks you to find the odd term out. The odd term is the one that does not obey the rule followed by the others. Such problems assess the ability to detect a uniform pattern and then identify the single value that breaks it. Given Data / Assumptions: The series is 888, 440, 216, 104, 48, 22, 6. Exactly one term is inconsistent with the pattern used for the rest. Since the sequence decreases smoothly at first, subtraction or division likely plays an important role. We must detect a simple rule that works for most terms and see where it fails. Concept / Approach: One promising approach is to see if each term is derived from the previous one by halving and then subtracting a fixed number. If that pattern holds through several steps but breaks at one place, the number at that place is the odd term. For this series, halving and subtracting 4 gives a very clean pattern for most transitions, which we can verify step by step. Step-by-Step Solution: Step 1: From 888 to 440: half of 888 is 444, and 444 minus 4 equals 440. Step 2: From 440 to 216: half of 440 is 220, and 220 minus 4 equals 216. Step 3: From 216 to 104: half of 216 is 108, and 108 minus 4 equals 104. Step 4: From 104 to 48: half of 104 is 52, and 52 minus 4 equals 48. Step 5: From 48 to the next number, if the same rule continues, we expect half of 48 to be 24, and 24 minus 4 equals 20. Then from 20 we expect half of 20 to be 10, and 10 minus 4 equals 6. However, the given series has 22 instead of 20 before 6, so 22 breaks the pattern. Verification / Alternative check: If we reconstruct the ideal series using the rule (next term) = (previous term / 2) - 4, we obtain: 888, 440, 216, 104, 48, 20, 6. Every transition fits the same rule with no exceptions. Comparing this intended sequence with the given one, we see that only the fifth transition differs, where 22 appears instead of 20. The last term 6 is still reachable naturally from 20 by half and minus 4, reinforcing that 22 is the only value inconsistent with the underlying pattern. Why Other Options Are Wrong: Term 440 matches the rule from 888 and to 216. Term 216 fits the rule both from 440 and to 104. Term 104 is correctly obtained from 216 and leads correctly to 48. Term 48 is correctly derived from 104 by the rule. All these terms show correct application of the same operation. Only 22 cannot be obtained from 48 by halving and subtracting 4, and it also does not lead to 6 via this rule, making it the unique outlier. Common Pitfalls: Students sometimes compute only simple differences between terms and get lost in a non uniform pattern. Others may assume the rule changes mid series rather than looking for one consistent rule that works for almost all terms. Another mistake is to not check the last two transitions carefully, assuming the error must be earlier. However, in many questions the wrong term is placed near the end. Careful verification of every step using the same rule helps to confidently identify the odd term. Final Answer: The number that does not satisfy the consistent rule of halving and subtracting 4 is 22, so 22 is the odd term out.

Question 15

Find the odd term out of the series 4, 5, 9, 18, 32, 59.

Accepted Answer

Introduction / Context: This question provides a moderately increasing number series and asks for the odd term out, that is, the term that breaks the rule followed by the others. The series appears to involve incremental additions that may be based on squares of integers. Identifying that structure is the key to solving the problem correctly. Given Data / Assumptions: The series is 4, 5, 9, 18, 32, 59. Exactly one term is inconsistent with the underlying pattern. The incremental jumps between numbers suggest they might be related to perfect squares. We must find which number does not fit that pattern. Concept / Approach: We first calculate the differences between consecutive terms and see whether those differences themselves follow a clear rule. In this series, the differences appear close to 1^2, 2^2, 3^2, 4^2, 5^2. If we can confirm that idea by reconstructing the series using these squares, and if one term does not fit, that term must be the odd one out. This method of looking at difference sequences is very powerful in many number series questions. Step-by-Step Solution: Step 1: Compute consecutive differences: 5 - 4 = 1, 9 - 5 = 4, 18 - 9 = 9, 32 - 18 = 14, 59 - 32 = 27. Step 2: Compare these with squares: 1, 4, 9, 16, 25 are 1^2, 2^2, 3^2, 4^2, 5^2. Step 3: The differences 1, 4, 9, and 27 match 1^2, 2^2, 3^2, and 5^2 fairly closely, but the difference 14 does not match 4^2, which should be 16. Step 4: Construct the ideal series by adding successive squares: start with 4, add 1 to get 5, add 4 to get 9, add 9 to get 18, add 16 to get 34, and add 25 to get 59. Step 5: The ideal sequence is thus 4, 5, 9, 18, 34, 59. Comparing this with the given series, 32 is the only term that differs from the intended 34, so 32 is the odd term. Verification / Alternative check: Using the rule add n^2 for n from 1 onwards, we have: 4 + 1^2 = 5, 5 + 2^2 = 9, 9 + 3^2 = 18, 18 + 4^2 = 34, 34 + 5^2 = 59. Every step in this reconstruction uses a perfect square in ascending order. The resulting sequence is consistent and elegant, which is exactly the type of pattern examination questions are designed around. The given sequence deviates from this pattern only at the fifth term, where 32 is provided instead of 34. Why Other Options Are Wrong: Term 5 is obtained correctly from 4 by adding 1^2. Term 9 correctly follows from 5 by adding 2^2. Term 18 is exactly 9 plus 3^2. Term 59 is 34 plus 5^2 in the ideal series, and only differs through the error in the preceding term. Removing 59 would break the neat use of 5^2 as the final increment. Therefore, 32 is uniquely inconsistent with the rule of adding successive perfect squares, and the other options are necessary to maintain the pattern. Common Pitfalls: One error is to miscalculate squares or differences, which easily leads to confusion. Another is to assume the odd term must be at the end of the series instead of checking all positions carefully. Some learners also attempt to find multiplicative relations when the series is clearly built from additive increments. Focusing on how differences relate to basic sequences such as squares or cubes is often the best path to the solution. Final Answer: The term that breaks the pattern of adding consecutive perfect squares is 32, so 32 is the odd term out.

Question 16

In the following letter series, blanks represent missing letters: _tu_rt_s__usrtu_. Choose the option that supplies the missing letters in the correct order.

Accepted Answer

Introduction / Context: This question features an incomplete letter series with specific blanks to be filled. The correct option must supply letters that, when placed into the blanks in order, create a coherent and preferably repetitive pattern. Such questions test visual pattern recognition and the ability to reconstruct underlying repeating sequences from partial information. Given Data / Assumptions: The series is written as _tu_rt_s__usrtu_. There are six blanks, each to be filled by one letter. Each answer option gives six letters that must be inserted into the blanks from left to right. The resulting full string should follow a neat repeating pattern if the option is correct. Concept / Approach: The approach is to substitute each option into the blanks and then inspect the resulting string. The correct choice is usually the one that turns the entire sequence into a clean repetition of a small letter block. In this question, the letters t, u, s, r appear frequently, hinting at a repeated block such as rtus or usrt. Our goal is to find which option, when substituted, produces a regular repetition of such a block without inconsistencies. Step-by-Step Solution: Step 1: Represent the pattern with blanks as _ t u _ r t _ s _ _ u s r t u _ in a continuous form. Step 2: Take option rsurts, which has six letters: r, s, u, r, t, s. Step 3: Substitute these into the blanks in order. The final string becomes r t u s r t u s r t u s r t u s, which can be grouped as rtus repeated four times. Step 4: The block rtus is clearly and exactly repeated without interruption, which is a very strong indication of a correct option. Step 5: This repetition demonstrates that rsurts provides the missing letters in precisely the right order. Verification / Alternative check: To validate, we can test another option to see that it fails to produce such neat repetition. For example, substituting rsutrr will not yield a pure repetition of rtus or any other simple block, and irregular combinations of letters will appear. The same happens with rsurtr and rtusru, none of which simplifies into a clean repeated pattern across the entire string. Only rsurts transforms the series into rtusrtusrtusrtus, an exact repetition of a four letter block, confirming that this option is the correct choice. Why Other Options Are Wrong: Option rsutrr introduces extra r letters that break the uniform rhythm of rtus. Option rsurtr results in mixed segments that do not align as pure repetitions of a single block. Option rtusru changes the relative order of letters and fails to construct a consistent basic unit that can be repeated. Option rrtuss also fails to generate any obvious repeating structure. In all of these options, the finished sequences contain irregular segments that do not match standard exam expectations of a well structured series. Common Pitfalls: Some candidates try to reason only locally, checking a few letters before and after each blank, but do not inspect the global string after substitution. Others ignore the possibility of a repeating block and instead attempt to impose complex rules on a short segment. A systematic approach that tests each option and then looks for an overall repeating pattern is less error prone and much more efficient in such questions. Final Answer: The sequence of letters that correctly completes the series as a repetition of rtus is rsurts.

Question 17

Find the missing number in the series 1, 4, 27, ?.

Accepted Answer

Introduction / Context: This number series looks short but hides a powerful pattern based on exponents. Recognizing that the terms can be expressed as n raised to the power n provides the key insight. Such exponent based series often appear in competitive exams to test conceptual understanding of powers and sequences. Given Data / Assumptions: The series is 1, 4, 27, ?. We must find a single missing term after 27. The numbers are 1, 4, 27, all of which are natural candidates for representation as powers. The pattern likely relates the base and exponent in a simple way. Concept / Approach: We test whether each term can be written as n^n for some integer n. If that works for the known terms, then we can continue with the next integer value to obtain the missing term. This method is a standard trick when an apparently irregular set of numbers can be interpreted as unusual powers such as 3^3, 4^4, and so on. Step-by-Step Solution: Step 1: Express 1 as a power: 1 = 1^1. Step 2: Express 4 as a power: 4 = 2^2. Step 3: Express 27 as a power: 27 = 3^3. Step 4: We see a clear pattern that the nth term is n^n, where n increases by 1 each step. Step 5: For the fourth term, n = 4, so the missing number must be 4^4 = 4 * 4 * 4 * 4 = 256. Verification / Alternative check: List the sequence using the formula n^n explicitly. For n = 1, we get 1^1 = 1. For n = 2, 2^2 = 4. For n = 3, 3^3 = 27. For n = 4, 4^4 = 256. Every term matches the given series up to the third term and provides a natural continuation for the fourth term. There is no need for a more complex pattern, since this simple exponent rule already explains all known values. Why Other Options Are Wrong: Option 125 is 5^3, which would not follow directly after 3^3 if we treat the exponent as tied to the base. Option 625 is 5^4, again not corresponding to the next integer n = 4 in the n^n pattern. Option 404 has no meaningful representation as n^n with small integers. Option 81 equals 3^4 or 9^2, but that does not extend the observed 1^1, 2^2, 3^3 structure. Therefore, 256 is the only option that aligns perfectly with the pattern n^n. Common Pitfalls: Some learners may first think of perfect squares or cubes separately without noticing that the base and exponent are the same for each term. Others may attempt to use differences or ratios, which in this case are irregular and unhelpful. A good habit when dealing with 1, 4, 27, and similar numbers is to test whether they are small integer powers like 1^1, 2^2, 3^3, 4^4, which quickly reveals the intended rule. Final Answer: The missing term that continues the pattern n^n is 256.

Question 18

What will be the next term in the letter series BKS, DJT, FIU, HHV, __?

Accepted Answer

Introduction / Context: This question gives a series of three letter terms and asks for the next term. Each position within the three letter block follows its own pattern, and the correct answer must match all of them simultaneously. The problem checks knowledge of English alphabetical order and skill in tracking multiple letter sequences in parallel. Given Data / Assumptions: The series is BKS, DJT, FIU, HHV, __. Each term has exactly three letters. Each letter position first, second, third may follow its own linear pattern. We must complete the series with the triplet that continues all observed patterns. Concept / Approach: A systematic approach is to separate the triplets into three parallel sequences, one for the first letters, one for the second letters, and one for the third letters. We convert letters into their numerical positions and then look for constant differences. If each sequence follows a simple pattern such as adding a fixed integer, we can calculate the next letter for each position and recombine them into the required triplet. Step-by-Step Solution: Step 1: First letters: B, D, F, H correspond to 2, 4, 6, 8. Each step adds 2. Step 2: Continue this pattern: 8 + 2 = 10, which corresponds to J, so the next first letter is J. Step 3: Second letters: K, J, I, H correspond to 11, 10, 9, 8. Each step subtracts 1. Step 4: Continue this pattern: 8 - 1 = 7, which corresponds to G, so the next second letter is G. Step 5: Third letters: S, T, U, V correspond to 19, 20, 21, 22. Each step adds 1, so the next third letter is 23, corresponding to W. Thus the next term is JGW. Verification / Alternative check: Write the three independent sequences explicitly: first letters 2, 4, 6, 8, 10 (B, D, F, H, J), second letters 11, 10, 9, 8, 7 (K, J, I, H, G), third letters 19, 20, 21, 22, 23 (S, T, U, V, W). Each sequence is a simple arithmetic progression, with differences +2, -1, and +1 respectively. The term JGW therefore fits all three rules and is the unique continuation of the series. No other option satisfies the combination of these patterns. Why Other Options Are Wrong: Option IJX has first letter I, which would correspond to 9, not 10, breaking the +2 pattern for the first position. Option IGX also uses I as the first letter and therefore fails the same way. Option JGU has the correct first and second letters J and G, but its third letter U corresponds to 21, which does not extend the +1 pattern from V. Option KGX alters multiple sequences at once and does not match any of the needed next values. Only JGW preserves all three independent patterns. Common Pitfalls: Some candidates try to interpret each triplet as a whole and look for more complicated or visual patterns, which is not necessary here. Others may correctly track one or two positions but forget to verify the third. Confusing alphabetical positions or miscounting steps is also a common source of errors. Working position wise with explicit numerical positions for letters and checking consistency across all positions helps avoid these mistakes. Final Answer: The next term that continues all three positional patterns is JGW.

Question 19

In the following number series, find the wrong term: 26, 20, 16, 11, 8, 6, 5.

Accepted Answer

Introduction / Context: This question tests your understanding of number series where each term is generated from the previous one using a fixed pattern. Instead of extending the series, you are asked to identify the one term that does not follow the rule. Such questions are common in bank and SSC examinations because they test pattern recognition and careful comparison skills. Given Data / Assumptions: The series is: 26, 20, 16, 11, 8, 6, 5. Exactly one term is incorrect and must be identified. The underlying rule is expected to be simple and consistent. Concept / Approach: For wrong term problems, the most reliable approach is to look at the differences between consecutive terms and see if these differences follow a recognizable pattern. Often we see arithmetic progressions, geometric progressions, or systematic changes in differences, such as adding or subtracting consecutive integers. The term that breaks this simple rule is the wrong one. Step-by-Step Solution: Step 1: Compute the differences between consecutive terms. 26 → 20: difference = 26 - 20 = 6. 20 → 16: difference = 20 - 16 = 4. 16 → 11: difference = 16 - 11 = 5. 11 → 8: difference = 11 - 8 = 3. 8 → 6: difference = 8 - 6 = 2. 6 → 5: difference = 6 - 5 = 1. Step 2: Collect these differences: 6, 4, 5, 3, 2, 1. Step 3: Observe that if the series was correct, the differences should ideally form a simple decreasing pattern such as 6, 5, 4, 3, 2, 1. Step 4: To obtain decreasing differences 6, 5, 4, 3, 2, 1 from the starting value 26, the sequence should be: 26, 20, 15, 11, 8, 6, 5. Step 5: Therefore the correct third term should be 15, not 16. Hence 16 is the inconsistent value. Verification / Alternative check: If we replace 16 with 15, the differences become: 26 - 20 = 6, 20 - 15 = 5, 15 - 11 = 4, 11 - 8 = 3, 8 - 6 = 2, 6 - 5 = 1. This gives a clean descending sequence of differences, which is a very natural and exam friendly pattern. This confirms that 16 is indeed the wrong term and 15 would be the expected correct term in that position. Why Other Options Are Wrong: 26, 20, 11, 8, 6, and 5 all fit perfectly once the third term is corrected to 15 because the differences around them match the required descending pattern. None of these values disturb the simple 6, 5, 4, 3, 2, 1 difference structure, so they cannot be considered as the wrong term in the series. Common Pitfalls: A common mistake is to assume the first term is wrong simply because it is the largest, or to look for multiplicative patterns when additive differences are much more natural in this type of question. Another frequent error is to stop checking after one or two differences instead of examining the full set. Always compute all consecutive differences so that the hidden structure is clearly revealed before deciding which number is incorrect. Final Answer: The number that breaks the clean descending pattern of differences is 16, so 16 is the wrong term in the given series.

Question 20

Find the next number in the series: 5, 8, 16, 19, 57, 60, ....

Accepted Answer

Introduction / Context: This number series question asks you to determine the next term by identifying the rule that transforms each number into the next. Many competitive exams use such patterns where operations alternate between addition and multiplication. Recognizing that structure quickly is the key to solving the problem efficiently. Given Data / Assumptions: The sequence is: 5, 8, 16, 19, 57, 60, ? Exactly one next term is to be found. A single consistent rule, possibly alternating operations, generates the series. Concept / Approach: When the jumps between numbers vary widely, it often indicates alternating operations such as add then multiply, or multiply then add. Examining the differences and ratios between consecutive terms helps reveal this pattern. Here, the values sometimes increase slightly and sometimes jump sharply, which strongly suggests an add then multiply structure. Step-by-Step Solution: Step 1: Compare 5 and 8. We see 5 + 3 = 8. Step 2: Compare 8 and 16. We see 8 × 2 = 16. Step 3: Compare 16 and 19. We see 16 + 3 = 19. Step 4: Compare 19 and 57. We see 19 × 3 = 57. Step 5: Compare 57 and 60. We see 57 + 3 = 60. Step 6: The pattern is now clear: +3, ×2, +3, ×3, +3, ×4, and so on, with the multiplier increasing by 1 each time. Step 7: To obtain the missing term, follow the pattern after the last visible step. From 60, we must multiply by 4. Step 8: Compute 60 × 4 = 240. Verification / Alternative check: Write the operations explicitly under the series: 5 (+3) 8 (×2) 16 (+3) 19 (×3) 57 (+3) 60 (×4) 240. We see a stable structure: addition of 3 every second step, and multiplication by 2, then 3, then 4. This is a very standard pattern in reasoning questions, so the value 240 fits perfectly and there is no contradiction at any step. Why Other Options Are Wrong: Values such as 188, 256, and 180 do not satisfy a simple, consistent sequence of alternating operations starting from 5. If we plug in any of these alternatives and try to work backward, the multiply steps or add steps would become irregular or fractional, which is unlikely for a well constructed exam series. Only 240 preserves the neat +3, ×2, +3, ×3, +3, ×4 pattern. Common Pitfalls: Students sometimes look only at first differences, which here are 3, 8, 3, 38, 3, ... and appear confusing. The correct strategy is to also consider multiplication, especially when some jumps are very large compared to others. Another pitfall is forcing a complicated high level formula, while exam setters usually prefer very simple alternating patterns that can be spotted by careful inspection. Final Answer: Following the alternating pattern of adding 3 and multiplying by increasing integers, the next term in the series is 240.

Number Series Questions