Question

There are 50 students in a class, of which 40 are boys. The average weight of the class is 44kg and that of the girls is 40kg. Find the average weight of the boys.

Answer 1

It is given that

Total number of students = 50

So total number of girls = 50 – 40 = 10

Average weight of the class = 44kg

So the total weight = 44 (50) = 2200kg

Average weight of 10 girls = 40kg

So total weight = 40 (10) = 400kg

We know that total weight of 40 boys = total weight of 50 students – total weight of 10 girls

By substituting the values

Total weight of 40 boys = 2200 – 400 = 1800kg

So we get

Average weight of boys = total weight of 40 boys/ number of boys

By substituting the values

Average weight of boys = 1800/40 = 45kg

Therefore, the average weight of boys = 45kg.