A father's age is one year more than 5 times of his son's age.  After 3 years, the father's age would be 2 years less than four times the son's age.  Find the present age of the father.

31

At present :

⇒ F = 5 S + 1     ..................(i)

After 3 years:

⇒ F + 3 = 4 (S + 3) - 2

⇒ F = 4 S + 12 - 5

⇒ 5 S + 1 = 4 S + 7                 (from (i))

⇒ S = 6

⇒ Therefore, age of Father = 5 S + 1 = (5 × 6) + 1 = 31 years