Question

The average weight of a class having 100 students is 40 kg. The number of boys in the class is 60 and the number of girls is 40. The average weight of boys is 45. Find the average weight of girls.

• A. 34 kg
• B. 33 kg
• C. 32.5 kg
• D. 30 kg

Answer 1

The correct option is C

32.5 kg

Given, the average weight of boys is 45 kg and the average weight of a class is 40 kg.

Let the average weight of girls be y.

$⟹\frac{(45\times 60)+(y\times 40)}{100}=40$

$⟹2700+40y=4000$

$⟹y=\frac{1300}{40}$

$⟹y=32.5kg$