The number of boys and girls in a class are in the ratio 7:5. The numb

1.	The number of boys and girls in a class are in the ratio 7:5. The number of boys is 8 more than the number of girls. What is the total class strength?
Answer» Let the common ratio between the number of boys and numbers of girls be x. Number of boys = 7x Number of girls = 5x According to the given question, Number of boys = Number of girls + 8 ∴ 7x = 5x + 8 On transposing 5x to L.H.S, we obtain 7x − 5x = 8 2x = 8 On dividing both sides by 2, we obtain 2x/2x = 8/2 x = 4 Number of boys = 7x = 7 × 4 = 28 Number of girls = 5x = 5 × 4 = 20 Hence, total class strength = 28 + 20 = 48 students

The number of boys and girls in a class are in the ratio 7:5. The number of boys is 8 more than the number of girls. What is the total class strength?

Answer»

Let the common ratio between the number of boys and numbers of girls be x.

Number of boys = 7x

Number of girls = 5x

According to the given question,

Number of boys = Number of girls + 8

∴ 7x = 5x + 8

On transposing 5x to L.H.S, we obtain

7x − 5x = 8

2x = 8

On dividing both sides by 2, we obtain

2x/2x = 8/2

x = 4

Number of boys = 7x = 7 × 4 = 28

Number of girls = 5x = 5 × 4 = 20

Hence, total class strength = 28 + 20 = 48 students