Question

In a school, `4/5` of the students are boys, and the number of girls is 100. Find the number of boys.

Answer 1

Let the total number of boys and girls = x

Total number of boys = `4/5` of x = `(4"x")/5`

According to question, the total strength of the school,

`"x"-(4"x")/5=100`

`(5"x"-4"x")/5=100`

`"x"/5=100`

⇒ x = 500

∴ Number of boys = total strength − girls

= 500 − 100

= 400.