Question

The no. of boys and girls in a class are in the ratio 7:5. The no. of boys is 8 more than girls. What is the total class strength?

Answer 1

Let the no. of girls be y,

So,

No. of boys = 8+y.

8+y:y=7:5

8+y/y=7/5

On cross multiplication,

40+5y=7y

40= 7y-5y

2y= 40

y=20.

Therefore, no. of boys =28 and no. of girls =20.

Total strength of the class =28+20=48.

Answer 2

no. of girls be x
no. of boys will be =8+x
now,
7/5=(8+x)/x
7*x=5 (8+x)
x=20
no. of boys will be=8+20=28
total strength wll be=20+28=48