Question

The average age of sons and their father is 20 years. If the average age of sons is 10 years, find the age of their father.​

Answer 1

The father's age is 30 years

Explanation:

Given:

1. The average age of son and father is 20 years

2. If the average age of son is 10 years

To find:

The age of their father.​

Solution:

==> Let, the father be, x

==> Son = y

==> $Average=\frac{x+y}{2}$

==> Average = 20

==> $20=\frac{x+y}{2}$

==> 20×2 = x+y

==> 40 = x+y

==> Son age is 10 years

==> y = 10

==> 40 = x+y

==> 40 = x+10

==> x = 40-10

==> x=30 years

The father's age is 30 years