Question

The sum of ages of a father and son is 40 years. Four years ago, the product of their ages was four times the father’s age at that time. The present age of the father is ?​

Answer 1

age of father be :x

age of son be :y

x+y =40-eq1

condition 1: four years ago

fathers age is 4x

age of son is y

4x+y =40

4x+y =40 _eq 2

now substitute the y value in eq 1

x+4x-40=40

5x =80

x =80/5

x=16