Question

The present ages of a father and a son are in the ratio 7:3, and they will be in the ratio 2:1 after 10 years. Then the present age of father (in years) is (3 Points)

Answer 1

Answer:

The present age of father is 70 years

The present age of Son is 30 years

Explanation:

Let,

The present age of father = 7x

The present age of Son = 3x

After 10 years

The age of father = 7x + 10

The age of Son = 3x + 10

They will be in the ratio = 2 : 1

So,

⇒ $\frac{7x + 10}{3x + 10} = \: \frac{2}{1}$

⇒ 1 (7x + 10) = 2 (3x + 10)

⇒ 7x + 10 = 6x + 20

⇒ 7x - 6x = 20 - 10

⇒ x = 10

★ Value of 7x :

⇒ 7 (10)

⇒ 7 × 10

⇒ 70

★ Value of 3x :

⇒ 3 (10)

⇒ 3 × 10

⇒ 30

Therefore,

The present age of father is 70 years

The present age of Son is 30 years

Answer 2

Answer:

Let the present age of the father be 7x

The present age of the son is 3x

After 10 years,

2(3x + 10) = 7x + 10

6x + 20 = 7x + 10

- x = - 10

x = 10

Present age of father is 7x = 7(10) = 70

Present age of son is 3x = 3(10) = 30

Hope this helps...