To solve this problem, first we know that there are 3 counselors for every 24 campers. To get from 3 campers to 9 campers, you would need to multiply 3 by 3. If you do this with the campers, you would also need to multiply the counselors (24) by 3 as well. 24 times 3 = 72.
So, if there are 9 counselors, there would need to be 72 campers.