Question

the number of boys and girls are in the ratio 7:5.the number of boys are 8more than girls. find total strength of the class.

Answer 1

Let the number of boys be 7a

Number of girls = 5a

According to question,

7a - 5a = 8

=> 2a = 8

=> a = 4

Number of boys = 4 × 7 = 28

Number of girls = 5 × 4 = 20

Total strength of class = 28 + 20 = 48

Answer 2

let no of girls=x
then no of boys=x+8
(x+8)/x=7/5
ie 5x+40=7x
x=20
x+8=28
so total strength=20+28=48