Question

In a class of 40 students, the ratio of boys to girls is 3:2. The average marks scored by boys is 42, and that by girls is 46. What is the average marks scored by the whole class?

• A. 43.4
• B. 43.6
• C. 43.8
• D. 44

Answer 1

The Correct Option is B

In a class of 40 students, the ratio of boys to girls is 3:2. This means there are \(\frac{3}{5} \times 40 = 24\) boys and \(\frac{2}{5} \times 40 = 16\) girls.

The average marks scored by boys is 42, so the total marks scored by boys is \(24 \times 42 = 1008\).

The average marks scored by girls is 46, so the total marks scored by girls is \(16 \times 46 = 736\).

The total marks scored by the whole class is \(1008 + 736 = 1744\).

The average marks scored by the whole class is \(\frac{1744}{40} = 43.6\).

Answer 2

Let the number of boys be $3x$ and the number of girls be $2x$. 

Since $3x + 2x = 40$, $x = 8$. 

There are 24 boys and 16 girls. 

Average = $\frac{(24 \times 42) + (16 \times 46)}{40} = 43.6$.