At a camp, the directors advertise that they have 3 counselors for every 20 campers. If the camp expects 120 campers, how many counselors should they hire?

Turn it into a ratio.

The beginning ratio is 3:20, because there are 3 counselors for every 20 campers.

Then, you do x:120, x representing the number of counselors.

You have to multipy 20 by 6 to get 120, so you multiply 3 by 6 to get x.

Therefore, there are 18 counselors if there are 120 campers.