3:

In Biology class, the girl to boy ratio is 3 to 10. If there are a total of 52 students, how many boys are there?

40 boys

Step-by-step explanation:

the ratio at first is 3 girls to 10 boys so you can use multiplication and addition to figure this out.

3 times 4 equals 12

10 x 4 = 40

whatever you multiply on one ratio you do to the other ratio. 40 + 12 = 52

Now the question is asking how many BOYS are there.

there are 40 boys.