Question

3 years ago the ratio of ages of the father to son is 5 : 1 and after 6 years the ratio of age of father to son will be 13 : 5. Find the present age of the son.

1. 7 years
2. 9 years
3. 12 years
4. 14 years
5. None of these

Answer 1

Correct Answer - Option 2 : 9 years

Given:

The ratio of ages of the father to son 3 years before = 5 : 1

The ratio of ages of the father to son after 6 years = 13 : 5

Calculation:

Let the ages of father and son 3 years before be 5x years and x years respectively.

Then, (5x + 3 + 6)/(x + 3 + 6) = 13/5

⇒ 25x + 45 = 13x + 117

⇒ 25x – 13x = 117 – 45

⇒ 12x = 72

⇒ x = 6

Age of father 3 years ago = 5 × 6

⇒ 30 years

Age of son 3 years ago = 1 × 6

⇒ 6 years

Then, Present age of son = 6 + 3

⇒ 9 years

∴ The present age of son is 9 years.