Question

In the seventh grade, the ratio of girls to boys is 7:5. If there are 21 girls in the seventh grade, how many boys are there?

Answer 1

There are 15 boys in the 7th grade class

Answer 2

We first should find how 7 relates to the 21 girls.

To do this we can divide.

The 21 girls by the 7 ratio 

21 divided by 7 is 3

So 1 out of 7 in the ratio is 3 girls

We can now move this over to the boys.

If 1 means 3, and their are a ratio of 5 boys

We do 5 x 3,

Which equal 15.

Their are 15 boys in 7th grade.

Hope this helps!
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