The sum of the ag

Let the present ages of the man and son be ‘a’ and ‘b’ respectively.

Given, sum of the ages of a man and his son is 45 years.

⇒ a + b = 45                    .............(1)

Ans, five years ago, the product of their ages was four times the man’s age at the time.

⇒ (a – 5)(b – 5) = 4(a – 5)

⇒ b – 5 = 4

⇒ b = 9 years

Thus, a = 45 – 9 = 36 years