Question

Three years ago, a man was 5 times the age of his son. Four years hence, he will be thrice his son's age. Find the present ages of the man and his son.

Answer 1

Let the present age of the man be M years and his sons age be S years. 

Then, as per the question description, 

M - 3 = 5 (S-3 ) ...... (i) 

M + 4 =3 (S+4 ) ...... (ii) 

From (i), we get: M + 12 = 5 S 

⇒ S = `("M" + 12)/5`  .........(iii)

From (ii), we get: M - 8 = 3S

Putting (iii) above, we get: M - 8 = `(3 (M + 12))/5`

⇒ 5M - 40 = 3M + 36 

⇒  2M = 76 

⇒ M =38 years and hence,  S= 10 years