The ratio of boy to girls in a class is 3 : 2. there are 15 boys in the class. how many total boys and girls are in the class? a) 15 b) 23 eliminate c) 25 d) 35

If the ratio is 3:2, put 15:?
This is how we set up proportions.
Now, divide your number of boys, 15, by the ratio of boys, 3.
This is how we find the dilation.
Since we end up with 5, we know the scale factor.
Multiply 2 by 5, and you get 10.
Add 10 and 15, you get 25.
Your answer is C.) 25.