Question 1

Mother–daughter equation system – A mother is five times her daughter’s present age. After 5 years she will be three times her daughter’s age. Find the mother’s current age.

Accepted Answer

Introduction / Context: This is a standard two-equation ages setup with current and future ratios. Solving carefully yields exact present ages without guessing. Given Data / Assumptions: Let daughter = D, mother = M. M = 5D (now). M + 5 = 3(D + 5) (after 5 years). Concept / Approach: Substitute M from the first equation into the second and solve for D; then compute M. Step-by-Step Solution: 5D + 5 = 3D + 15.2D = 10 ⇒ D = 5.M = 5D = 25. Verification / Alternative check: After 5 years: mother 30, daughter 10; 30 = 3 × 10 holds. Why Other Options Are Wrong: They do not meet both the present 5× and future 3× constraints simultaneously. Common Pitfalls: Adding 5 to only one side or mixing present and future ages in a single step. Final Answer: 25 years

Question 2

Four children at 4-year intervals – The sum of their present ages is 60. What is the age of the youngest child?

Accepted Answer

Introduction / Context: When children are born at equal intervals, their ages form an arithmetic progression. Summation formulas for APs make such problems quick to solve. Given Data / Assumptions: Let youngest = x. Then ages are x, x + 4, x + 8, x + 12. Sum = 60. Concept / Approach: Add the four-term AP and solve for x. Equally spaced terms keep the algebra simple. Step-by-Step Solution: x + (x + 4) + (x + 8) + (x + 12) = 60.4x + 24 = 60 ⇒ 4x = 36 ⇒ x = 9. Verification / Alternative check: Actual ages: 9, 13, 17, 21; sum = 60. Why Other Options Are Wrong: They do not satisfy the sum with 4-year spacing. Common Pitfalls: Using 3 terms or spacing by 3 years accidentally. Always match the stated interval. Final Answer: 9

Question 3

Siblings with fixed gap – Nikhil is 8 years younger than Rohan. How old will Rohan be when he is exactly twice as old as Nikhil?

Accepted Answer

Introduction / Context: We are asked for the age Rohan will be at the moment he is twice Nikhil, given a constant present gap. Modeling “t years from now” for both brothers and equating produces a single linear equation in t that directly yields Rohan’s target age. Given Data / Assumptions: Nikhil = Rohan − 8 (present ages). We want t such that Rohan + t = 2(Nikhil + t). Concept / Approach: Substitute Nikhil in terms of Rohan, solve for the calendar time t, then compute Rohan’s age at that time. Step-by-Step Solution: R + t = 2((R − 8) + t) = 2R − 16 + 2t.Bring terms together: R + t − 2R + 16 − 2t = 0 ⇒ −R − t + 16 = 0 ⇒ R + t = 16.Therefore, when the condition holds, Rohan will be 16 years old. Verification / Alternative check: If Rohan is 16, Nikhil is 8 (because the gap is 8). 16 = 2 × 8, so the condition is satisfied. Why Other Options Are Wrong: They do not meet the 2× condition alongside the fixed 8-year gap. Common Pitfalls: Solving for t and reporting t instead of Rohan’s age at that time. The question explicitly asks for Rohan’s age. Final Answer: 16 years

Question 4

Sum now and ratio in the past – The sum of the present ages of a father and son is 60. Six years ago the father was five times the son. After 6 years, what will be the son’s age?

Accepted Answer

Introduction / Context: We have a present-time sum and a past-time ratio. Converting both into equations in present variables and solving yields the son’s current age, from which we can project six years into the future. Given Data / Assumptions: Let F = father, S = son (present ages). F + S = 60. Six years ago: F − 6 = 5(S − 6). Asked: S + 6. Concept / Approach: From the past ratio: F = 5S − 24. Substitute into the sum to solve for S, then add 6. Step-by-Step Solution: F = 5S − 24.(5S − 24) + S = 60 ⇒ 6S = 84 ⇒ S = 14.After 6 years: S + 6 = 20. Verification / Alternative check: Check the past relation: F = 46; six years ago 40 and 8 → 40 = 5 × 8, true. Present sum: 46 + 14 = 60, true. Why Other Options Are Wrong: They do not follow from the unique solution S = 14. Common Pitfalls: Dropping the −6 term on only one side of the past equation or forgetting to compute “after 6 years.” Final Answer: 20

Question 5

Ages ratio now and after a fixed period: Samir and Saurabh are currently in the ratio 8 : 15 (respectively). After 9 years, their ages will be in the ratio 11 : 18. Find the difference between their present ages (in years).

Accepted Answer

Introduction / Context: Problems on ages frequently use ratios at two different times to derive present ages. By translating the statement into linear equations, we can solve for a single scaling factor and then compute the required difference. Given Data / Assumptions: Present ratio (Samir : Saurabh) = 8 : 15. After 9 years, ratio becomes 11 : 18. Let present ages be 8k and 15k. Both ages advance by the same 9 years in the future scenario. Concept / Approach: The core idea is that if present ages are in ratio a : b, then after t years they will be (a k + t) and (b k + t). Setting this over the target ratio yields a single equation in k. Once k is known, exact ages and differences follow immediately. Step-by-Step Solution: 1) Assume Samir = 8k, Saurabh = 15k.2) After 9 years: (8k + 9) / (15k + 9) = 11 / 18.3) Cross-multiply: 18(8k + 9) = 11(15k + 9).4) Expand: 144k + 162 = 165k + 99.5) Rearrange: 63 = 21k ⇒ k = 3.6) Present ages: 8k = 24, 15k = 45. Difference = 45 − 24 = 21 years. Verification / Alternative check: Check the future ratio: 24 + 9 = 33 and 45 + 9 = 54. Then 33 : 54 simplifies by 3 to 11 : 18, matching the condition. Why Other Options Are Wrong: 20/22/24/18 years do not reproduce the future ratio 11 : 18 when back-computed. Common Pitfalls: A frequent mistake is adding 9 to the ratio numbers instead of to the actual ages. Another error is simplifying ratios incorrectly before forming the equation. Final Answer: 21 years

Question 6

Present-to-future age ratio between a father and daughter: The ratio of the current ages of Suresh and his daughter is 2 : 1. Six years hence, their ages would be in the ratio 23 : 13. Determine Suresh’s present age (in years).

Accepted Answer

Introduction / Context: This is a standard two-time age-ratio problem that converts neatly into one linear equation in a single variable by expressing present ages via a common multiplier and then advancing both by the same number of years. Given Data / Assumptions: Suresh : Daughter now = 2 : 1. After 6 years, ratio = 23 : 13. Let present ages be 2x and x. Concept / Approach: Use present ratio to set 2x and x. Advance both by 6, and equate the future ratio to 23/13. Solve for x to recover exact ages. Choose the option that matches Suresh’s present age. Step-by-Step Solution: 1) Present ages: Suresh = 2x, Daughter = x.2) After 6 years: (2x + 6) / (x + 6) = 23 / 13.3) Cross-multiply: 13(2x + 6) = 23(x + 6).4) 26x + 78 = 23x + 138 ⇒ 3x = 60 ⇒ x = 20.5) Suresh now = 2x = 40 years. Verification / Alternative check: Future ages: 46 and 26, which indeed reduce to 23 : 13 when divided by 2. The data are consistent. Why Other Options Are Wrong: 35/45/50/38 years fail to produce the required future ratio of 23 : 13 when back-checked. Common Pitfalls: Do not change the difference between ages when moving into the future; only add the same increment to both. Also avoid inverting the ratio accidentally. Final Answer: 40 years

Question 7

Father–son age relation across time: A father is presently 34 years older than his son. Twelve years ago, the father's age was 18 times the age of his son. What is the son's present age (in years)?

Accepted Answer

Introduction / Context: Age problems mixing “difference now” and “multiple in the past” are classic linear-equation setups. A fixed difference today remains fixed at any time shift, while multiplicative relationships apply at the specified time reference. Given Data / Assumptions: If son's present age is s, father's present age is s + 34. Twelve years ago: father's age = 18 × (son's age). Concept / Approach: Translate the past condition using present variables shifted by 12 years: (s + 34 − 12) = 18 (s − 12). Solve the resulting linear equation for s. Step-by-Step Solution: 1) Past condition: s + 22 = 18(s − 12).2) Expand: s + 22 = 18s − 216.3) Rearrange: 22 + 216 = 18s − s ⇒ 238 = 17s.4) Solve: s = 238 / 17 = 14.5) Therefore, son's present age is 14 years. Verification / Alternative check: 12 years ago, son was 2; father was 36. Indeed, 36 = 18 × 2. The numbers are consistent. Why Other Options Are Wrong: 12/16/18/20 years do not satisfy the “18 times” condition when verified with the 34-year present difference. Common Pitfalls: Forgetting to subtract 12 from both ages or mishandling the difference (which remains 34 at any time) often leads to wrong results. Final Answer: 14 years

Question 8

Two-person age ratio with known difference: The ratio of the ages of two persons is 4 : 7. The older person is 30 years more than the younger. What is the sum of their present ages (in years)?

Accepted Answer

Introduction / Context: When an age ratio and an absolute difference are both given, the scaling factor for the ratio can be found directly from the difference of the ratio parts. Then compute individual ages and their sum. Given Data / Assumptions: Present ratio = 4 : 7. Difference between actual ages = 30 years (older minus younger). Let ages be 4x and 7x (older = 7x). Concept / Approach: The difference in actual ages equals the difference in ratio parts times the scale x: (7 − 4) x = 3x. Set 3x = 30 to find x, then calculate the sum. Step-by-Step Solution: 1) 3x = 30 ⇒ x = 10.2) Ages are 4x = 40 and 7x = 70.3) Sum = 40 + 70 = 110. Verification / Alternative check: Ratio check: 40 : 70 simplifies by 10 to 4 : 7. Difference is 30, matching the statement. Why Other Options Are Wrong: 100/120/130/90 do not satisfy both the required ratio and the 30-year difference simultaneously. Common Pitfalls: Confusing which is older/younger or adding the difference to the ratio numbers instead of to actual ages can derail the calculation. Final Answer: 110

Question 9

Family ages with fixed differences: A father is 30 years older than his first son, and the first son is 10 years older than the second son. If the sum of their present ages is 95 years, find the father’s current age.

Accepted Answer

Introduction / Context: Linear age chains with fixed differences are straightforward: define the youngest as a variable, express others relative to it, and use the given total to solve. This avoids ratio complications. Given Data / Assumptions: Let the second son be y. First son = y + 10. Father = y + 40 (since 30 more than first son). Total of three ages = 95. Concept / Approach: Sum the three expressions and solve the resulting one-variable linear equation. Step-by-Step Solution: 1) y + (y + 10) + (y + 40) = 95.2) 3y + 50 = 95 ⇒ 3y = 45 ⇒ y = 15.3) Father = y + 40 = 15 + 40 = 55 years. Verification / Alternative check: First son = 25; second son = 15; father = 55. Sum = 55 + 25 + 15 = 95 (correct). Differences match the problem. Why Other Options Are Wrong: 45/50/65/60 years make the total or differences inconsistent with the statement. Common Pitfalls: Mixing up the direction of differences (who is older) or mis-summing the three expressions can lead to errors. Final Answer: 55 years

Question 10

Parent–child ratio now and in the future: Deepak’s present age is three times that of his son. Five years hence, their ages will be in the ratio 34 : 13 (Deepak : Son). Find Deepak’s current age.

Accepted Answer

Introduction / Context: Another two-time ratio problem: represent present ages by a multiplier, shift both by the same future increment, and equate to the given future ratio. Solve for the multiplier and then compute the exact ages. Given Data / Assumptions: If son = x, Deepak = 3x (present). After 5 years: (3x + 5) : (x + 5) = 34 : 13. Concept / Approach: Convert the ratio into an equation and solve for x. Multiply as needed to recover Deepak’s age. Step-by-Step Solution: 1) (3x + 5) / (x + 5) = 34 / 13.2) Cross-multiply: 13(3x + 5) = 34(x + 5).3) 39x + 65 = 34x + 170 ⇒ 5x = 105 ⇒ x = 21.4) Deepak = 3x = 63 years. Verification / Alternative check: Future ages: Deepak 68, son 26 → 68 : 26 = 34 : 13, confirming the condition. Why Other Options Are Wrong: 58/60/68/54 do not produce the exact 34 : 13 ratio after 5 years when checked. Common Pitfalls: Confusing which value the multiplier x represents or adding 5 to the ratio instead of the ages are frequent mistakes. Final Answer: 63 years

Question 11

Mother–daughter age relation with past multiple: A mother is 25 years older than her daughter. Five years ago, the mother’s age was 6 times the daughter’s age. What is the mother’s current age?

Accepted Answer

Introduction / Context: The mix of a fixed present difference and a past multiplicative relationship yields a single linear equation. Solve using a present variable and a time shift to the past. Given Data / Assumptions: Daughter now = x; Mother now = x + 25. Five years ago: mother = 6 × daughter. Concept / Approach: Set (x + 25 − 5) = 6(x − 5) and solve for x; then compute the mother’s current age. Step-by-Step Solution: 1) x + 20 = 6x − 30.2) 50 = 5x ⇒ x = 10.3) Mother now = x + 25 = 35 years. Verification / Alternative check: Five years ago: daughter = 5, mother = 30; indeed, 30 = 6 × 5. The data are consistent. Why Other Options Are Wrong: 25/29/32/40 do not satisfy the 6× condition when checked backwards with a present difference of 25. Common Pitfalls: Forgetting to subtract 5 from both ages or mixing up whose age is a multiple of whose can lead to errors. Final Answer: 35 years

Question 12

Two persons with a fixed present difference and future ratio: The difference between the present ages of P and Q is 4 years. After 5 years, the ratio P : Q will be 9 : 8. Find the present age of P.

Accepted Answer

Introduction / Context: We combine a fixed present difference with a future ratio, leading to a single variable equation. Sometimes the computed value does not align with any listed numeric option; in such cases, “None of these” is correct if the arithmetic is sound. Given Data / Assumptions: P − Q = 4 (assume P is older; if not, algebra reveals consistency). After 5 years: (P + 5) / (Q + 5) = 9 / 8. Concept / Approach: Express P as Q + 4, substitute into the future ratio, and solve for Q. Recover P and compare with options. Step-by-Step Solution: 1) (Q + 4 + 5) / (Q + 5) = 9 / 8 ⇒ (Q + 9) / (Q + 5) = 9 / 8.2) Cross-multiply: 8(Q + 9) = 9(Q + 5).3) 8Q + 72 = 9Q + 45 ⇒ 27 = Q.4) Then P = Q + 4 = 31. Verification / Alternative check: Future ages: P = 36, Q = 32 ⇒ 36 : 32 = 9 : 8 (true). Hence P = 31 is exact. Why Other Options Are Wrong: 24/30/32 years are not equal to 31 years; the only valid choice is None of these. Common Pitfalls: Students sometimes misread “difference is 4” as “ratio difference” or add 5 to the ratio instead of ages. Maintain proper algebraic structure. Final Answer: None of these (P = 31 years)

Question 13

Parent–child present multiple with past multiple: A father’s present age is three times his son’s age. Five years ago, the father’s age was four times the son’s age. What is the son’s current age?

Accepted Answer

Introduction / Context: When present and past multiplicative relationships are given, set present ages with a variable, shift by the time span, and enforce the earlier multiple to solve for that variable. Given Data / Assumptions: Father now = 3s; Son now = s. Five years ago: (3s − 5) = 4(s − 5). Concept / Approach: Rearrange the past-time equation to isolate s. Step-by-Step Solution: 1) 3s − 5 = 4s − 20.2) 15 = s.3) Therefore, the son’s present age is 15 years. Verification / Alternative check: Five years ago: father = 40, son = 10 → indeed 40 = 4 × 10; now father = 45, son = 15 (3 × 15). Why Other Options Are Wrong: 20/18/12/10 do not satisfy both the present triple and the past quadruple relationship simultaneously. Common Pitfalls: Forgetting to subtract 5 from each age, or assuming both multiples hold at the same time, results in contradictions. Final Answer: 15 years

Question 14

Ages in a given ratio with known total; future ratio requested: Shami, Nammi and Pammi are currently in the age ratio 3 : 4 : 5. Their total age is 48 years. What will be the ratio of their ages 8 years from now?

Accepted Answer

Introduction / Context: When a ratio and total are given, compute the common unit, obtain actual present ages, then add the future increment to each and reduce to the simplest ratio for the future time. Given Data / Assumptions: Present ratio = 3 : 4 : 5. Total = 48 years. Future time shift = +8 years for each person. Concept / Approach: The sum of ratio parts is 3 + 4 + 5 = 12. One unit equals 48 / 12 = 4. Present ages are 12, 16, and 20. Add 8 to each and reduce. Step-by-Step Solution: 1) Present ages: 3×4 = 12; 4×4 = 16; 5×4 = 20.2) After 8 years: 20, 24, 28.3) Simplify 20 : 24 : 28 by dividing by 4 ⇒ 5 : 6 : 7. Verification / Alternative check: All three increased equally by 8, so internal differences remain consistent; the simplified ratio is correct. Why Other Options Are Wrong: 4:5:6 and 6:7:8 correspond to different increments; 5:7:8 changes differences improperly; 3:5:7 is unrelated. Common Pitfalls: Forgetting to simplify the final ratio or incorrectly applying the total to find the unit are common issues. Final Answer: 5 : 6 : 7

Question 15

Average ages across two and three persons with time shift: Five years ago, the average age of Ram and Shyam was 20 years. Now, the average age of Ram, Shyam and Mohan is 30 years. Find Mohan’s age 10 years from now.

Accepted Answer

Introduction / Context: Average-based age problems are solved by converting averages into sums and then using time shifts to adjust sums appropriately. The goal is to isolate the third person’s present age, then push it forward. Given Data / Assumptions: 5 years ago: average(Ram, Shyam) = 20 ⇒ sum then = 40. Therefore, sum now for Ram and Shyam = 40 + 2×5 = 50. Now: average(Ram, Shyam, Mohan) = 30 ⇒ total now = 90. Concept / Approach: Compute present sum of the two from their past average; subtract from the current total of three to find Mohan’s present age; then add 10 years. Step-by-Step Solution: 1) Present sum (Ram + Shyam) = 50.2) Present sum (Ram + Shyam + Mohan) = 90.3) Mohan now = 90 − 50 = 40.4) Mohan after 10 years = 50. Verification / Alternative check: Back-checking: If Mohan is 40 now, the current average of the three is (50 + 40) / 3 = 90/3 = 30, matching the statement. Why Other Options Are Wrong: 45/35/55/40 do not correspond to “Mohan 10 years hence” based on consistent sums. Common Pitfalls: Forgetting to add 10 years to the two-person sum when moving forward from “5 years ago” or misinterpreting average as ratio can cause mistakes. Final Answer: 50 years

Question 16

Known present difference and past ratio: The difference between the current ages of a boss and his subordinate is 16 years. Four years ago, their ages were in the ratio 11 : 7 (Boss : Subordinate). Find the subordinate’s present age.

Accepted Answer

Introduction / Context: Combining a present absolute difference with a past-time ratio yields a solvable single-variable equation. Represent the boss as subordinate plus 16, then apply the ratio four years ago. Given Data / Assumptions: Let subordinate now = s; boss now = s + 16. Four years ago: (s + 16 − 4) : (s − 4) = 11 : 7. Concept / Approach: Set up (s + 12) / (s − 4) = 11 / 7 and solve for s. Step-by-Step Solution: 1) 7(s + 12) = 11(s − 4).2) 7s + 84 = 11s − 44.3) 128 = 4s ⇒ s = 32.4) Subordinate’s present age = 32 years. Verification / Alternative check: Four years ago: subordinate 28, boss 44 ⇒ ratio 44 : 28 = 11 : 7 (correct). The present difference is 16, consistent. Why Other Options Are Wrong: 28/36/40/30 do not satisfy both the difference and the ratio conditions upon verification. Common Pitfalls: Not subtracting 4 from both ages, or flipping the ratio order, are typical errors. Final Answer: 32 years

Question 17

Average of a team under replacements: A cricket team’s average age is 27 years. Two players aged 24 and 27 are replaced by new players aged 23 and 28. What is the new average age of the team?

Accepted Answer

Introduction / Context: Average problems with replacements can often be handled by comparing total sums before and after. If the net change in total age is zero, the average remains unchanged (provided the team size is unchanged). Given Data / Assumptions: Original team average = 27 years (team size constant). Removed: 24 and 27; Added: 23 and 28. Concept / Approach: Compute the total change: (23 + 28) − (24 + 27) = 51 − 51 = 0. Therefore, team total remains the same and so does the average. Step-by-Step Solution: 1) Outgoing sum = 24 + 27 = 51.2) Incoming sum = 23 + 28 = 51.3) Net change = 0 ⇒ Average unchanged = 27 years. Verification / Alternative check: If the number of players stays the same, unchanged total implies unchanged average. This is independent of the actual team size. Why Other Options Are Wrong: Any value other than 27 would require a non-zero net change in total age. Common Pitfalls: Students sometimes attempt to average the four numbers directly; only the net change in totals relative to team size matters. Final Answer: 27 years

Question 18

Linked present and future ages with a given fraction: The present age of X is 2/3 of Y's present age. After 6 years, X will be 46 years old. Find Y's current age.

Accepted Answer

Introduction / Context: This age problem uses a present fractional relationship and a future absolute age for one person. Determine X now from the future value, then use the fraction to compute Y now. Given Data / Assumptions: X now = (2/3) × Y now. X after 6 years = 46 ⇒ X now = 40. Concept / Approach: Back-calculate X's present age, then invert the fraction to find Y: Y = (3/2) × X. Step-by-Step Solution: 1) X now = 46 − 6 = 40.2) 40 = (2/3) × Y ⇒ Y = 40 × (3/2) = 60.3) Therefore, Y's present age is 60 years. Verification / Alternative check: After 6 years: X = 46, Y = 66; the original fraction at present is 40/60 = 2/3 (correct). Why Other Options Are Wrong: 40/56/100/48 do not satisfy the fraction 2/3 when X is 40 now. Common Pitfalls: Confusing “X is 2/3 of Y” with “Y is 2/3 of X” or forgetting to move back 6 years before applying the fraction. Final Answer: 60 years

Question 19

Four friends with overlapping averages and a sum condition: A, B, C, and D are four friends. Average age of A and C is 35 years (so A + C = 70). Average age of B and D is 40 years (so B + D = 80). The average age of B, C and D is 40 years (so B + C …

Accepted Answer

Introduction / Context: Multiple overlapping average conditions combined with a balancing sum (A + D = B + C) form a compact linear system. The key is to translate each statement into equations and solve systematically. Given Data / Assumptions: A + C = 70. B + D = 80. B + C + D = 120. A + D = B + C. Concept / Approach: Use B + C + D = 120 and A + D = B + C to eliminate variables stepwise. Express A in terms of D, then find C and B, ensuring all constraints hold. Step-by-Step Solution: 1) From A + D = B + C and B + C + D = 120 ⇒ (A + D) + D = 120 ⇒ A + 2D = 120 ⇒ A = 120 − 2D.2) From A + C = 70 ⇒ (120 − 2D) + C = 70 ⇒ C = 2D − 50.3) From B + D = 80 ⇒ B = 80 − D.4) Check B + C + D = (80 − D) + (2D − 50) + D = 30 + 2D; set equal to 120 ⇒ 2D = 90 ⇒ D = 45.5) Then A = 120 − 90 = 30; C = 2×45 − 50 = 40; B = 80 − 45 = 35. Verification / Alternative check: A + C = 30 + 40 = 70; B + D = 35 + 45 = 80; B + C + D = 35 + 40 + 45 = 120; A + D = 30 + 45 = 75 = B + C (35 + 40). All conditions satisfied. Why Other Options Are Wrong: Other tuples violate at least one of the sums or the balancing condition A + D = B + C. Common Pitfalls: Mixing averages with totals incorrectly or skipping the A + D = B + C constraint leads to inconsistent sets. Final Answer: 30, 35, 40, 45

Question 20

Mother–daughters age relation via average and difference: The difference between a mother’s age and the sum of her two daughters’ present ages is 6 years. The average age of the two daughters is 22. What is the mother’s present age?

Accepted Answer

Introduction / Context: This problem links average and difference. Convert the average of the two daughters to their sum, add the difference, and obtain the mother’s age directly. Given Data / Assumptions: Average of two daughters = 22 ⇒ sum = 44. Mother’s age − (sum of daughters) = 6. Concept / Approach: Let M be the mother’s age and S be daughters’ sum. The statement gives M − S = 6, with S = 44. Hence M = 44 + 6. Step-by-Step Solution: 1) Compute daughters’ sum: 2 × 22 = 44.2) M − 44 = 6 ⇒ M = 50. Verification / Alternative check: Check: M − (sum daughters) = 50 − 44 = 6 (correct). Why Other Options Are Wrong: 40/44/46/52 do not meet the exact difference when paired with sum 44. Common Pitfalls: Confusing “difference between mother and sum of daughters” with “difference between mother and average” causes wrong results. Final Answer: 50

Problems on Ages Questions