Question

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

Answer 1

let the girls and boys be x and y respectively
now
7x=5y
x+8=y
7x=5(x+8)
7x=5x+40
2x=40
x=20 = girls

Answer 2

Let the number of boys be 7x and girls be 5x.

According to the question,

7x = 5x + 8

⇒ 7x – 5x = 8

⇒ 2x = 8

⇒ x = 8/2

⇒ x = 4

Therefore, Number of boys = 7×4 = 28

And, Number of girls = 5×4 = 20

Total number of students = 20+28 = 48