Question

A man's age is now four times that of his son. In 18 years it will be double that of his son. the present age of the son is?
1. 6 years 
2. 7 years
3. 8 years
4. 9 years

Answer 1

Correct Answer - Option 4 : 9 years

GIVEN:
Man's age = 4 × Son's age

Man's age after 18 years = 2 × son's age after 18 years

EXPLANATION:

Let the age of the son be x years 

∴ Man's age be 4x years

A.T.Q 

4x + 18 = 2 (x + 18)

4x + 18 = 2x + 36 

x = 9 years

∴ son's present age is 9 years