Question 1

Translate and solve a “percent of” comparison: If 8% of 96 equals ? of 1/25, determine the value of ? (treat “of” as multiplication).

Accepted Answer

Introduction / Context: The phrase “? of 1/25” is read as multiplication: (?)*(1/25). This question asks you to match the value of 8% of 96 with a product involving the unknown and the fraction 1/25, then solve for the unknown. Given Data / Assumptions: Compute 8% of 96. Equate it to (?)*(1/25). Find the value of ? accordingly. Concept / Approach: First evaluate 8% of 96 numerically. Then solve the linear equation (?)*(1/25) = computed value. Multiply both sides by 25 to isolate ?. Step-by-Step Solution: 8% of 96 = 0.08 * 96 = 7.68.Set (?)*(1/25) = 7.68.Multiply both sides by 25: ? = 7.68 * 25 = 192. Verification / Alternative check: Check: 192 * (1/25) = 192/25 = 7.68, which equals 8% of 96. The solution is consistent. Why Other Options Are Wrong: 19.2, 7.68, 1.92 are intermediate or related numbers, but none equal the actual value of ?. Among the listed options, only “None of these” can be correct since 192 is not presented as a selectable answer. Common Pitfalls: Interpreting “of” incorrectly or assuming the question asks for 8% of 96 directly. Always translate the statement into an equation first. Final Answer: None of these

Question 2

Reverse percentage relationship: If A is 90% of B, then B is what percent of A?

Accepted Answer

Introduction / Context: This is a classic “reverse percent” problem. Given A as a certain percent of B, we are asked to express B as a percent of A. Such conversions test ratio inversion skills. Given Data / Assumptions: A = 90% of B ⇒ A = 0.9B. We want B as a percent of A. Concept / Approach: From A = 0.9B, isolate B in terms of A. Then convert the resulting factor to a percentage by multiplying by 100. Step-by-Step Solution: A = 0.9B ⇒ B = A / 0.9.B/A = 1 / 0.9 = 1.111…As percent: 1.111… * 100% = 111.1% (recurring). Verification / Alternative check: Pick B = 100 for a quick check. Then A = 90. Now B as a percent of A is 100/90 * 100% = 111.1%. Why Other Options Are Wrong: 90% reverses in the wrong direction (that would be A as a percent of B). 190%, 120% are unrelated overestimates. 101.1% is far too small; the inverse of 0.9 must exceed 1.10. Common Pitfalls: Directly “adding 10%” or guessing. Always invert the factor correctly: if A = kB, then B = (1/k)A. Final Answer: 111.1%

Question 3

Identity with mutual percentages: Show that (A% of B + B% of A) is equal to which of the following?

Accepted Answer

Introduction / Context: This question checks comfort with symbolic percentages and distributive reasoning. Recognizing symmetrical expressions helps in algebraic simplification. Given Data / Assumptions: We interpret A% of B as (A/100) * B, and B% of A as (B/100) * A. We need the simplified sum in familiar percentage form. Concept / Approach: Write both terms explicitly and factor common pieces. Because multiplication is commutative, A * B and B * A are the same. Combine like terms to reach a compact result. Step-by-Step Solution: A% of B = (A/100) * B.B% of A = (B/100) * A.Sum = (A/100)B + (B/100)A = (AB/100) + (AB/100) = 2AB/100.Thus, the sum equals 2% of AB. Verification / Alternative check: Use numbers: Let A = 10 and B = 50. Then A% of B = 10% of 50 = 5; B% of A = 50% of 10 = 5; total = 10. Meanwhile, 2% of AB = 2% of 500 = 10 — matches. Why Other Options Are Wrong: A% of B or B% of A alone accounts for only half the sum. “AB% of 3” is not a meaningful standard expression. A% of A + B% of B is unrelated to the symmetric cross terms here. Common Pitfalls: Confusing “A% of B + B% of A” with “(A+B)% of (A+B)”. Keep symbols aligned with their operands. Final Answer: 2% of AB

Question 4

Find the whole from a part percentage: If 31% of a number is 46.5, what is the number?

Accepted Answer

Introduction / Context: Given a part of a whole expressed via a percentage, we are asked to recover the original whole. This is the reverse of “finding a percentage of a number.” Given Data / Assumptions: x is the unknown number. 31% of x equals 46.5. Concept / Approach: Translate “31% of x” to 0.31 * x. Then solve the simple linear equation 0.31x = 46.5 by dividing both sides by 0.31. Step-by-Step Solution: 0.31x = 46.5.x = 46.5 / 0.31.Compute: 46.5 / 0.31 = 4650 / 31 = 150. Verification / Alternative check: Check forward: 31% of 150 = 0.31 * 150 = 46.5, confirming the value. Why Other Options Are Wrong: 155, 160, 165, 180 produce 31% values different from 46.5. Common Pitfalls: Misplacing the decimal when converting 31% to 0.31 or attempting to divide by 31 (instead of 0.31). Keep percent-to-decimal conversion precise. Final Answer: 150

Question 5

Find a quantity “60% less than” a given number: Which number is 60% less than 80?

Accepted Answer

Introduction / Context: “60% less than 80” means we remove 60% of 80 from 80. This phrasing often trips students who instead compute 80 − 60 or apply the percent incorrectly. Given Data / Assumptions: Base number: 80. Reduction: 60% of 80. Concept / Approach: Compute the retained portion: 100% − 60% = 40%. So the result is 40% of 80. Equivalently, result = 0.40 * 80. Step-by-Step Solution: Compute 60% of 80: 0.60 * 80 = 48.Subtract from 80: 80 − 48 = 32.Alternatively: 40% of 80 = 0.40 * 80 = 32. Verification / Alternative check: Since we keep 40% of 80, and 10% is 8, then 40% is 4 * 8 = 32 — same result. Why Other Options Are Wrong: 48 equals the amount subtracted, not the final remainder. 42 and 12 are unrelated to the correct 40% retention. 20 would be 75% less than 80, not 60% less. Common Pitfalls: Confusing “60% less than 80” with “80% of 60” or simply subtracting 60. Always apply the percent to the base number, then subtract. Final Answer: 32

Question 6

Linked percentages across variables: If 90% of A equals 30% of B and B = C% of A, find the value of C.

Accepted Answer

Introduction / Context: This item connects two percentage relationships among A, B, and C. The goal is to express B as a percent of A once we compare 90% of A with 30% of B. Given Data / Assumptions: 0.90A = 0.30B. B = (C/100) * A. Concept / Approach: Solve the first equation for B in terms of A, then equate it to (C/100) * A. Cancel A (assuming A ≠ 0), and solve for C. Step-by-Step Solution: From 0.90A = 0.30B ⇒ B = (0.90/0.30)A = 3A.But B is also (C/100)A.So (C/100)A = 3A ⇒ C/100 = 3 ⇒ C = 300. Verification / Alternative check: Check: If B = 300% of A, then 30% of B = 30% of 3A = 0.90A, which matches the left side. Why Other Options Are Wrong: 900, 800, 600 are multiples that do not satisfy both relationships simultaneously. 150 would make B = 1.5A; then 30% of B would be 0.45A, not 0.90A. Common Pitfalls: Solving 0.90/0.30 incorrectly or forgetting that “B = C% of A” means (C/100) * A. Final Answer: 300

Question 7

Compare three quantities in different forms: Which is greatest among 33 1/3%, 4/15, and 0.35?

Accepted Answer

Introduction / Context: Comparing values presented as a percent, a fraction, and a decimal is a common skill. The easiest route is to convert all three to the same form (usually decimals) and then compare. Given Data / Assumptions: 33 1/3% = 1/3 = approximately 0.3333… 4/15 ≈ 0.2666… 0.35 is already a decimal. Concept / Approach: Convert each to decimal (or to percent) and compare numerically. Ensure adequate precision to avoid ties caused by rounding. Step-by-Step Solution: 33 1/3% = 33.333…% = 0.3333…4/15 = 0.2666…0.35 = 0.3500…Hence, 0.35 > 0.3333… > 0.2666… Verification / Alternative check: As percents: 33 1/3% ≈ 33.33%; 4/15 ≈ 26.67%; 0.35 = 35%. The largest is 35%. Why Other Options Are Wrong: 33 1/3% is smaller than 0.35. 4/15 is the smallest of the three. “Cannot be compared” is incorrect; precise decimal equivalents make comparison straightforward. Common Pitfalls: Misconverting the mixed percent or the fraction. Write at least three to four decimal places for a clean comparison. Final Answer: 0.35

Question 8

Solve for the missing factor in a percent equation: Find ? in 45 × ? = 25% of 900.

Accepted Answer

Introduction / Context: This is a direct application of percentages and basic algebra. We equate a product to a percentage of a known number and solve for the unknown factor. Given Data / Assumptions: Equation: 45 * ? = 25% of 900. 25% = 0.25. Concept / Approach: First evaluate the right-hand side (RHS). Then divide by 45 to find the unknown. Step-by-Step Solution: Compute RHS: 25% of 900 = 0.25 * 900 = 225.So 45 * ? = 225.? = 225 / 45 = 5. Verification / Alternative check: Check: 45 * 5 = 225, which equals 25% of 900. The equation balances. Why Other Options Are Wrong: 16.20 and 2.5 arise from arithmetic slips (e.g., dividing by 9 or 18 incorrectly). 4 gives 180 on the left, not 225. 500 is wildly off; it confuses percent with multiplication by 100. Common Pitfalls: Miscomputing 25% of 900; remember that 25% is one-fourth, and 900/4 = 225. Final Answer: 5

Question 9

Recover the base amount from a small percent value: If 0.5% of A equals 85 paise, find A in rupees.

Accepted Answer

Introduction / Context: The value is given in paise while the options are in rupees. We must convert units correctly and then invert the percentage operation to find the base amount. Given Data / Assumptions: 0.5% of A = 85 paise. 100 paise = 1 rupee ⇒ 85 paise = Rs. 0.85. Concept / Approach: Translate 0.5% to a decimal (0.005). Then solve 0.005 * A = 0.85 for A by dividing both sides by 0.005. Step-by-Step Solution: 0.005 * A = 0.85.A = 0.85 / 0.005.A = 170. Verification / Alternative check: Check: 0.5% of 170 = 0.005 * 170 = 0.85 rupees = 85 paise — consistent. Why Other Options Are Wrong: Rs. 17 produces 0.085 rupees (8.5 paise), not 85 paise. Rs. 1.70 and Rs. 4.25 are far too small. Rs. 850 would give 4.25 rupees (425 paise), overshooting the target. Common Pitfalls: Forgetting to convert paise to rupees or misplacing the decimal when converting 0.5% into 0.005. Final Answer: Rs. 170

Question 10

Percent of a percent: What percent is 3% of 5%?

Accepted Answer

Introduction / Context: Here we multiply two percentages. Remember that a percent is itself a fraction of 100. So “3% of 5%” means 0.03 times 5%, yielding a very small percentage. Given Data / Assumptions: 3% = 0.03. 5% = 5 percent (we will keep the percent form in the result). Concept / Approach: Compute 0.03 * 5% = (0.03 * 5)%. Multiply the numeric parts and retain the percent sign for the final expression. Step-by-Step Solution: 0.03 * 5 = 0.15.Therefore, 3% of 5% = 0.15%. Verification / Alternative check: Convert both to decimals: 3% of 5% = 0.03 * 0.05 = 0.0015 = 0.15% when expressed back as a percent. Why Other Options Are Wrong: 15% and 1.5% are 100× and 10× too large, respectively. 0.015% is 10× too small. Common Pitfalls: Treating percent signs as ordinary numbers without converting to decimals first. Always remember that % introduces a factor of 1/100. Final Answer: 0.15%

Question 11

Solve for the missing multiplier: 75% of 480 equals (?) × 15. Find (?).

Accepted Answer

Introduction / Context: We equate a known percent of a number to a simple product and solve for the unknown multiplicative factor. This is an algebraic one-step solve after computing the percent value. Given Data / Assumptions: LHS: 75% of 480. RHS: (?) × 15. Concept / Approach: Compute the left-hand side first. Then divide by 15 to isolate (?). Verify if the result is present among the options. Step-by-Step Solution: 75% of 480 = 0.75 * 480 = 360.So (?) × 15 = 360 ⇒ (?) = 360 / 15 = 24. Verification / Alternative check: Check: 24 × 15 = 360, matching 75% of 480. Therefore, the correct value is 24. Why Other Options Are Wrong: 32 and 18 produce 480 and 270, not 360. 360 is the LHS value, not the multiplier (?); it would correspond to 360 × 15, which is incorrect. The exact correct value 24 is not listed among the main options, so “None of these” is appropriate. Common Pitfalls: Stopping after computing 360 and selecting it as the answer. The question asks for the multiplier (?), not the percent result. Final Answer: None of these

Question 12

Unit conversion with percentages: 30 quintals is what percent of 2 metric tonnes?

Accepted Answer

Introduction / Context: This question mixes unit conversion (quintal vs metric tonne) with percentage comparison. Correctly converting to the same unit before computing the percentage is vital. Given Data / Assumptions: 1 quintal = 100 kg. 1 metric tonne = 1000 kg. We compare 30 quintals with 2 metric tonnes. Concept / Approach: Convert both quantities to kilograms, compute the ratio (quantity/base), and then express as a percentage by multiplying by 100. Step-by-Step Solution: 30 quintals = 30 * 100 kg = 3000 kg.2 metric tonnes = 2 * 1000 kg = 2000 kg.Percentage = (3000 / 2000) * 100% = 1.5 * 100% = 150%. Verification / Alternative check: Since 3000 kg is one and a half times 2000 kg, the percent must be 150%. Why Other Options Are Wrong: 15% and 1.5% reverse or misplace the factor of 100. 30% misinterprets the “30” from 30 quintals and treats it as a direct percent. 75% corresponds to 3/4, not 3/2. Common Pitfalls: Comparing with mismatched units or forgetting that percent is per hundred. Always reduce to the same unit first. Final Answer: 150%

Question 13

Form an equation from wording: A number exceeds 20% of itself by 40. What is the number?

Accepted Answer

Introduction / Context: We are told that a number is larger than 20% of itself by a fixed amount. This translates directly into a simple linear equation in one variable. Given Data / Assumptions: x is the unknown number. x − 20% of x = 40. Concept / Approach: Convert the percent to decimal, collect like terms, and solve. This is equivalent to finding the value whose 80% equals 40. Step-by-Step Solution: x − 0.20x = 40.0.80x = 40.x = 40 / 0.80 = 50. Verification / Alternative check: Compute 20% of 50 = 10; then 50 exceeds 10 by 40 — matches the condition exactly. Why Other Options Are Wrong: 60, 80, 320, 200 do not satisfy x − 0.20x = 40 when substituted. Common Pitfalls: Mistaking “exceeds 20% of itself by” as “is 20% of itself plus 20%” or similar misreads. Carefully translate the sentence. Final Answer: 50

Question 14

Symmetry property in percentages: x% of y is equal to y% of what quantity?

Accepted Answer

Introduction / Context: This is a well-known symmetry: x% of y equals y% of x. The question asks you to recognize this and state the quantity for which y% produces the same result as x% of y. Given Data / Assumptions: x% of y = (x/100) * y. We seek Q such that y% of Q equals the same value. Concept / Approach: Set (y/100) * Q = (x/100) * y, then solve for Q. Cancellation of y (assuming y ≠ 0) shows the equality directly. Step-by-Step Solution: (y/100) * Q = (x/100) * y.Cancel y/100 on both sides ⇒ Q = x. Verification / Alternative check: Numeric example: Let x = 30 and y = 50. Then 30% of 50 = 15. Also, 50% of 30 = 15. Hence, Q must be x. Why Other Options Are Wrong: 100x and x/100 scale the value improperly. y/100 and y are unrelated to the required equivalence. Common Pitfalls: Overcomplicating with extra factors of 100. Keep the percent-as-fraction representation clear. Final Answer: x

Question 15

Match two partial percentages: 12.5% of 192 equals 50% of what number?

Accepted Answer

Introduction / Context: We are equating two percent-of quantities. Compute one side, then solve the simple percentage equation on the other side to find the unknown number. Given Data / Assumptions: LHS: 12.5% of 192. RHS: 50% of ? Concept / Approach: Use the fact that 12.5% = 1/8 and 50% = 1/2 to speed up arithmetic. Compute 1/8 of 192; then set 1/2 * ? equal to that value and solve. Step-by-Step Solution: 12.5% of 192 = (1/8) * 192 = 24.Set 50% of ? = 24 ⇒ (1/2) * ? = 24.Thus, ? = 48. Verification / Alternative check: Check: Half of 48 is 24 — matches 12.5% of 192. Why Other Options Are Wrong: 96 gives 50% of 96 = 48, not 24. 24 confuses the left-hand result with the unknown. 36 yields 18 for 50%, not 24. Common Pitfalls: Misreading 12.5% as 12.5/100 without simplifying to 1/8, which is a convenient equivalence. Final Answer: 48

Question 16

Scale one percentage to another: If 37 1/2% of a number is 900, then find 62 1/2% of the same number.

Accepted Answer

Introduction / Context: The percentages 37 1/2% and 62 1/2% are complementary to 100% and can be expressed as simple fractions (3/8 and 5/8). This makes computing the whole and rescaling straightforward. Given Data / Assumptions: 37.5% = 3/8 of the number equals 900. We seek 62.5% = 5/8 of the number. Concept / Approach: From (3/8) * N = 900, solve for N. Then compute (5/8) * N for the desired percentage. Step-by-Step Solution: (3/8) * N = 900 ⇒ N = 900 * 8 / 3 = 2400.Now compute (5/8) * N = (5/8) * 2400 = 1500. Verification / Alternative check: Check: 3/8 of 2400 is 900 (given) and 5/8 of 2400 is 1500. The two add to the whole 2400, confirming consistency. Why Other Options Are Wrong: 1200 and 1350 are undershoots of 5/8 of 2400. 540 corresponds to 22.5% of 2400, not 62.5%. 1800 equals 75% of 2400, not 62.5%. Common Pitfalls: Not recognizing the handy fraction forms of 37 1/2% and 62 1/2%, which greatly simplify the arithmetic. Final Answer: 1500

Question 17

Effect of subtracting a percent from a quantity: Subtracting 6% of A from A is equivalent to multiplying A by what factor?

Accepted Answer

Introduction / Context: When a fixed percent of a quantity is removed, the remainder is a specific fraction (or decimal) of the original. This is a routine transformation used frequently in successive change problems. Given Data / Assumptions: You remove 6% of A from A. We want the multiplicative factor applied to A to obtain the remainder. Concept / Approach: Subtracting 6% means retaining 100% − 6% = 94% of A. Converting 94% to decimal gives the multiplier. Step-by-Step Solution: A − 6% of A = A − 0.06A = (1 − 0.06)A.(1 − 0.06)A = 0.94A.Hence the factor is 0.94. Verification / Alternative check: Example: If A = 100, subtract 6% (6) leaves 94, which is 0.94 * 100. Why Other Options Are Wrong: 9.4 and 94 are increases by factors of 10 or 100. 0.094 is 9.4% of A, not 94%. 0.964 is 96.4%, not 94%. Common Pitfalls: Misplacing decimals when converting percents to decimal multipliers. Always divide the percent by 100 to get the factor. Final Answer: 0.94

Question 18

Compare two computed quantities: By how much is 30% of 80 greater than four-fifths of 25?

Accepted Answer

Introduction / Context: This question compares two simple computed values: a percentage of one number and a fraction of another. The task is to find the absolute difference and identify by how much the first exceeds the second. Given Data / Assumptions: Quantity 1: 30% of 80. Quantity 2: 4/5 of 25. We require Quantity 1 − Quantity 2. Concept / Approach: Evaluate each expression separately using standard percent and fraction conversions, then subtract. Keep arithmetic tidy to avoid sign mistakes. Step-by-Step Solution: 30% of 80 = 0.30 * 80 = 24.4/5 of 25 = (0.8) * 25 = 20.Difference = 24 − 20 = 4. Verification / Alternative check: As mental math: 10% of 80 is 8, so 30% is 3 * 8 = 24. Meanwhile, 1/5 of 25 is 5, so 4/5 is 4 * 5 = 20. The difference is 4. Why Other Options Are Wrong: 2, 10, 15 are not equal to the computed difference 4. 0 would require the two quantities to be equal, which they are not. Common Pitfalls: Mixing up percent of 80 (using 0.8 instead of 0.30) or miscomputing four-fifths of 25. Work carefully with each conversion. Final Answer: 4

Question 19

A shop cuts the marked price of an article by 10%. By what exact percentage must the reduced price be increased to restore it to the original (former) price?

Accepted Answer

Introduction / Context: This is a classic reverse-percentage question from retail mathematics. If a price is first decreased and then increased, the required percentage to return to the original value is not the same as the initial decrease. We need to compute the exact increase that undoes a 10% cut. Given Data / Assumptions: Initial price (assume) = P. First operation: 10% reduction. Second operation: an unknown percentage increase that restores the price to exactly P. All changes are on the current price at each step (successive percentage changes). Concept / Approach: After a 10% cut, the new price is 90% of P, i.e., 0.9P. To get back to P, we must find r such that (1 + r) * 0.9P = P. Solving for r gives r = 1/9 = 0.111… = 11 1/9%. The key idea is that reverse percentages are computed relative to the reduced base, not the original base. Step-by-Step Solution: New price after cut = 0.9P.Suppose we increase by r (in decimal): 0.9P * (1 + r) = P.(1 + r) = P / (0.9P) = 1 / 0.9 = 10/9.r = 10/9 − 1 = 1/9 = 0.111… = 11 1/9%. Verification / Alternative check: Take P = 100. After 10% cut → 90. Increase by 11 1/9% → 90 * (1 + 1/9) = 90 * (10/9) = 100, which matches the original price. Why Other Options Are Wrong: 11%: Slightly low; 90 * 1.11 = 99.9, not fully restored. 10%: Reversing 10% needs more than 10% because the base is smaller. 12 1/2%: Too high; would overshoot beyond the original. Common Pitfalls: Assuming the reverse percentage equals the original cut. Always compute on the changed base. Final Answer: 11 1/9%

Question 20

A broker's income stays constant while commission rate rises from 4% to 5%. By what percentage did the business volume (turnover) slump?

Accepted Answer

Introduction / Context: This problem links a broker’s income to commission rate and business volume. Income = rate * business volume. If income remains unchanged while the rate increases, volume must fall proportionally. We quantify that fall (slump) as a percentage. Given Data / Assumptions: Initial commission rate = 4%. New commission rate = 5%. Income before = Income after. Business volume is directly proportional to income/rate. Concept / Approach: Let the original business volume be B. Original income = 0.04B. With the new rate 5%, to keep income same we need 0.05B’ = 0.04B → B’ = (0.04/0.05)B = 0.8B. The slump = (B − B’)/B = 0.2 = 20% decrease. Step-by-Step Solution: Income formula: I = rate * volume.Keep I constant: 0.04B = 0.05B’.Solve: B’ = (0.04/0.05)B = 0.8B.Percentage slump = (B − 0.8B)/B * 100% = 20%. Verification / Alternative check: Assume B = 100 units. Old income = 4. New rate = 5%. To earn income 4, required volume = 4/0.05 = 80. Fall from 100 to 80 is 20%. Why Other Options Are Wrong: 8% or 1%: Underestimate; ignores proportionality. 80%: Misinterpretation; that would imply business nearly collapsed. Common Pitfalls: Confusing percentage points with percentage change, or comparing new and old rates instead of equating incomes. Final Answer: 20%

Percentage Questions