The ratio of students to teachers is 4 to 2. If there are 400 students, how many teachers are there?

Answer 1

For every 4 students there are 2 teachers (or for every 2 students there is 1 teacher)

Multiply both number by 100

So for every 4*100 students there are 2*100 teachers. That is for .every 400 students there are 200 teachers

Answer 2

setup a ratio:

4/2 = 400/x

cross multiply and solve for x, i.e., x = 800/4 = 200. Keep students on top and teachers on bottom.