Question

the average age of a group of 13 boys is 13 when 2 more boys join the group. the average rose by 2 years the sum of the ages of two new boys

Answer 1

The sum of age of the two new boys = 56 years

Explanation:

The average age of a group of 13 boys = 13

The sum of age of the 13 boys = 13 * 13 = 169

The average age of a group of 15 boys = 15

The sum of age of the 15 boys = 15 * 15 = 225

The sum of age of the two new boys = 225 - 169 = 56 years