The sum of the present ages of a father and his son is 60 years. five years ago, father's age was four times the age of the son. So now the son's age will be-

Question: The sum of the present ages of a father and his son is 60 years. five years ago, father's age was four times the age of the son. So now the son's age will be-

Solution:
Let the present ages of son and father be x and (60 - x) years respectively.

Then,
(60 - x) - 5 = 4(x - 5)
⇒ 55 - x = 4x - 20
⇒ 5x = 75
∴ x = 15