At a certain camp, the counselor-to-camper ratio is 2 to 9. If the camp has 18 counselors, how many campers does it have?

At a certain camp, the counselor-to-camper ratio is 2 to 9. If the camp has 18 counselors, how many campers does it have?

For more practice with ratios, click here.

In this case, all we need to do is set up our ratio and be careful to keep our units straight:

$\dfrac{2\text{ counselors}}{9\text{ campers}}=\dfrac{18\text{ counselors}}{x\text{ campers}}$

Cross multiply and solve:

$2x=162$

$x=81$

So there are 81 campers at the camp.

PWN Test Prep