Question

Rohit was 4 times as old as his son 8 years ago. After 8 years, Rohit will be twice as old as his son. What are their present ages?

Answer 1

Let son's age 8 years ago be x years. 

Then, Rohit's age 8 years ago = 4x years. 

Son's age after 8 years = (x + 8) + 8 = (x + 16) years. 

Rohit's age after 8 years = (4x + 8) + 8 = (4x+ 16) years. 

2 (x + 16) = 4x + 16 

2x = 16 

x = 8. 

Hence, son's 'present age = (x + 8) = 16 years. 

Rohit's present age = (4x + 8) = 40 years.