Question

In a class of 40 ,there are 10 boys st age of 12 years ,12 at the age of 12.5 years and the rest at the age of 13. The average age of boys in the class is?

Answer 1

Number of boys = 40
There are 10 boys at the age of 12 years
= 10 x 12 = 120 years
There are 12 boys at the age of 12.5 years
= 12 x 12.5 = 150 years
The rest at the age of 13 years
(40-22) x 13
= 18 x 13 = 234 years

Total years = 120 + 150 + 234 = 504 years
Average age of the class = total years / number of boys
= 504 / 40
= 12.6 years.