Daya is 5 times as old as his son. Six years hence the sum of their ages will be 72 years. What is the present age of Daya's son?

Correct option is B

Given:

Daya is 5 times as old as his son.

Six years hence, the sum of their ages will be 72 years.

Solution:

Let the present age of Daya's son be x years.

Therefore, Daya's present age is 5x years (since Daya is 5 times as old as his son).

In 6 years:

Daya's age will be 5x + 6.

His son's age will be x + 6.

In 6 years, the sum of their ages will be 72 years. So:

(5x + 6) + (x + 6) = 72

5x + x + 6 + 6 = 72

6x + 12 = 72

6x = 60

x = 10

So, the present age of Daya's son is 10 years.

Thus the correct option is (b)  10 years