Hi!

First, we say that the number of students in class c = c, class b = b, and class a = a.

We can see that Class B has 50% more students than Class C. The ratio between them is 1.5:1, or 3:2(Class B: Class C).

Then we can look for the ratio between Class B and Class A. Class A also has 50% more students, making the ratio between them also 1.5:1, or 3:2(Class A: Class B).

Now we can look for the ratio between all three of them. Class B to Class C is 1.5:1. We can then multiply 1.5 by 1.5 again to get 2.25 as Class A.

2.25:1.5:1

2.25:1

**9:4 **is the ratio.

To check, we can pretend Class C has 8 students. Class B then has 12 students, and Class A has 18.

18:8

9:4