Question

The number of boys are in the ratio 9:4.there are 25more boys than girls.find the number of total students in the class

Answer 1

Here is your answer

Let the number of girls is x

Number of boys are x + 25

Ratio of boys to girls is 9:4

ATQ

$\frac{x + 25}{x} = \frac{9}{4} \\ 4x + 100 = 9x \\ 9x - 4x = 100 \\ 5x = 100 \\ x = \frac{100}{5} \\ \\ x = 20$
so
Number of Girls are 20
Number of boys are 20 +25
= 45

Total Students in the class = 45+ 20

= 65

Hope it helps you

Answer 2

Let the number of girls is x
Number of boys x + 25

$\frac{x + 25}{x} = \frac{9}{4} \\ 4x + 100 = 9x \\ 9x - 4x = 100 \\ 5x = 100 \\ x = 20$
Number of Girls = 20
Number of boys = 20 + 25 = 45

Total Students = 20 + 45 = 65

Hope it helps