This set of Aptitude Questions and Answers (MCQs) focuses on “Problems on Ages”. These questions are beneficial for various competitive exams, placement interviews, and entrance tests.

1. B is twice as old as A. C is twice as old as B. If the difference between ages of A and C is 12 years, find the age of b.

a) 8 years

b) 7 years

c) 6 years

d) 5 years

View Answer

Explanation: Let the ages of A, B and C be x, y and z.

Y = 2x, z = 2y

Z = 4x

Difference between ages of x and z = 12 years

4x – x = 12 years

3x = 12 years, x = 4 years

Y = 2x = 2 * 4 = 8 years

2. P is thrice as old as Q. The difference between the ages of P and Q is a multiple of 9. Find the minimum possible age of P, if it is known that Q’s age is an odd prime number.

a) 9 years

b) 10 years

c) 11 years

d) 12 year

View Answer

Explanation: Let the age of P and Q be x and y.

The minimum possible age of Q can be 3 as the age is a prime number and an odd number.

The minimum difference between their ages can be 9 as the number should be a multiple of 9.

P’s minimum possible age can be Q’s minimum possible age + minimum possible difference.

3 + 9 = 12 years

3. The sum of ages of 2 brothers is 45 years. If their ages are in a ratio 4:5, find their ages after 10 years.

a) 15, 30 years

b) 20, 25 years

c) 30, 35 years

d) 22, 23 years

View Answer

Explanation: Let their ages be x and y, respectively.

X:y = 4:5

x / 4 = y / 5

5x = 4y

X + y = 45

4(x + y) = 45 * 4 (multiplying both sides by 4)

4x + 4y = 180

4x + 5x = 180

9x = 180, x = 20

Y = 45 – x = 45 – 20 = 25

X = 20 years, y = 25 years

After 10 years:

X = 20 + 10 = 30 years

Y = 35 years

4. Ram and Raju are cousins. If it is known that Ram is 30 years younger than Raju and the ratio of their ages is 28:7. Find their ages after 5 years.

a) 20, 50

b) 30, 60

c) 45, 15

d) 15, 45

View Answer

Explanation: Let their ages be x and y, respectively.

X:y = 28:7

X / 28 = y / 7

7x = 28y

X = 28y / 7 = 4y

Difference between their ages = 30 years

X – y = 4y – y = 30

3y = 30

Y = 10

X = 4y = 10 * 4 = 40 years

After 5 years

X = 40 + 5 = 45 years

Y = 15 years

5. X’s age is 20% more than Y’s age. If the sum of their ages if 20 more than the difference of their ages, find their respective ages.

a) 12, 10

b) 18, 15

c) 24, 20

d) 30, 25

View Answer

Explanation: Let the ages of X and Y be p and q.

P = q + 20% of q

(P + q) – (p – q) = 20

P + q – p + q = 20

2q = 20

Q = 10

Y’s age = 10 years

X’s age is 20% more than Y’s age.

10 + 20% of 10

10 + 10 * 20 / 100

10 + 2 = 12

Their ages are 12, 10.

6. Out of 3 friends one is 12 years old. The ratio of the ages of the other 2 friends a and b is 3:4. If the youngest among them is 12 years old, find the minimum possible age of the eldest friend.

a) 25

b) 30

c) 35

d) 40

View Answer

Explanation: In the question it is given that first friend is 12 years old also the youngest among them but nowhere it is given that two friends are not of the same age. Thus, in this question it will be assumed that two friends are 12 years old. Of which one is the first mentioned and the other is a.

A is 12 years old.

A:b = 3:4

B = a / 3 * 4, = 12 / 3 * 4 = 16 years

Total of their age = 12 + 12 + 16 = 40

7. A branch of a company have 2 employees m and n. If it is known that the ages of m and n are in a ratio 3:12, and the sum of their ages is 7 years and 6 months. Find the age of n.

a) 5 years

b) 5.5 years

c) 6 years

d) 6.5 years

View Answer

Explanation: The total of their ages is given in a combination of years and months so the first step will be to convert the total in one unit, here months.

7 years and 6 months = 7 * 12 + 6 = 84 + 6 = 90 months

Ratio of ages of m and n = 3:12

m / 3 = n / 12

12m = 3n

4m = n

M + 4m = 90

5m = 90

M = 18

N = 4m = 4 * 18 = 72

72 months = 72 / 12 = 6 years

8. A and B are sisters born after the year 2010. If the sum of their ages will be 19 in the year 2025, What will be the age of A in 2030. It is known that in the year 2024 the ratio of their age is 7:10.

a) 12

b) 13

c) 14

d) 16

View Answer

Explanation: The sum of their ages in 2025 = 19 years

The sum of their ages in 2024 = (sum in 2025) – 2

19 – 2 = 17

Ratio of ages of a and b in 2024 = 7:10

A / 7 = b / 10

10a = 7b

A + b = 17 years

10 (a + b) = 17 * 10 (multiplying both sides by 10

10a + 10b = 170

7b + 10b = 170

17b = 170

B = 170 / 17 = 10

A = 7b / 10 = 7 * 10 / 10 = 7 years

Age of a in 2024 = 7

Age of a in 2030 = 7 + 6 = 13

9. The sum of ages of 2 friends A and B is 42. If the ratio between the sum and difference of their ages is 2:1, find the age of A.

a) 31.5

b) 32.5

c) 33.5

d) 34.5

View Answer

Explanation: Let the ages of A and B be x and y.

(X + y):(x – y) = 2:1

X + y = 2(x – y)

X + y = 2x – 2y

3y = x

X + y = 42 (given)

3y + y = 42

4y = 42

Y = 10.5

X = 3y = 3 * 10.5 = 31.5

10. If 2 members of a family are in a ratio 3:\(\frac {1}{2}\), and the average of their ages is 35. Find the total of their ages after 11 years.

a) 81 years

b) 92 years

c) 102 years

d) 89 years

View Answer

Explanation: The average ages of 2 members = 35

The total of their ages = 35 * 2 = 70 years

The ratio of their ages = 3:\(\frac {1}{2}\) = 6:1 (multiplying both sides by 2, to make the ratio in natural numbers)

6x + x = 70

7x = 70

X = 10, 6x = 60

The total of their ages after 11 years = (10 + 11) + (60 + 11) = 21 + 71 = 92 years.

**More Aptitude Questions and Answers on Ages:**

- Problems on Ages Questions (Set 2)
- Problems on Ages Questions (Set 3)
- Problems on Ages Questions (Set 4)
- Problems on Ages Questions (Set 5)
- Problems on Ages Questions (Set 6)

To practice all aptitude questions, please visit “1000+ Quantitative Aptitude Questions”, “1000+ Logical Reasoning Questions”, and “Data Interpretation Questions”.