Question

In a school there are between `24 and 40` students in a class. In one class the ratio of `" boys : girls "` is `4 : 7` How many students are there in that class?

Answer 1

There are 12 boys and 21 girls for a total of 33 students

Explanation:

Since there aren’t going to be fractions of people we can just count up using the whole numbers in the ratio and then check if the sum is between 24 and 40.

Let’s begin:

`4:7->4+7=11<24` not enough

`8:14->8+14=22<24` not enough

`12:21->12+21=33`

`24<33<40` in the correct range!

There are 12 boys and 21 girls for a total of 33 students

Answer 2

There are `33` students

Explanation:

If you divided the class into groups with `4` boys and `7` girls in each group, there will be `11` students in each group.

The total number of students in the class therefore must be a multiple of `11`.

The only multiple of `11` between `24 and 40` is `33`.

There are therefore `33` students.
`4/11 xx 33 = 12` are boys and

`7/11 xx 33 = 21` are girls.

`" "12: 21`

`= 4 :7`