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?

2 Answers
Oct 10, 2017

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

Oct 10, 2017

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