Question

if in a class 30 students the number of girls is one fifth of the number of the boys how many boys are there in the class

Answer 1

number of boys = x
number of girls = 1/5 x
so,

x + 1/5 x = 30
6x/5 = 30
x = 30 * 5/6 = 25

number of boy students = 25 boy students

Answer 2

let x = number of boys.......
x + (1/5)x = 30
multiplying both sides with 5

5 (x + (1/5)x ) = 30 * 5

5x + x = 150

6x = 150

x = 150/6

x = 25

hope it is helpful to u