The age of Mr. Ramesh is four times the age of his son. After ten years the age of Mr. Ramesh will be only twice the age of his son. Find the present age of Mr. Ramesh’s son.

A 10 years

B 20 years

C 5 years

D Cannot be determined

E None of these

Correct Answer: Option C

Let, age of Ramesh be R, and that of his son be S.

∴ R = 4S -------------------------1

After 10 years, their ages will be (R + 10) and (S + 10) respectively.

∴ (R + 10) = 2(S + 10)

⇒ R + 10 = 2S + 20

From 1,

⇒ 4S – 2S = 10

⇒ S = 5

Present age of the son is 5 years.