How many parent volunteers are needed for 135 teenagers?

Question

Your sorority is having a fall dance. The requirement for number of parent volunteers needed is 4 parents per 40 teenagers. How many parent volunteers are needed for 135 teenagers?

Answer 1

An easy way to look at this is that 4 parents to 40 teens is the same ratio as 1 parent to 10 teens. 

 

So if you have 130 teens, you'll need 13 parents.

 

What about the extra 5? Most likely your question is assuming they cannot go unsupervised, so you'll need another parent to watch them, even though that one parent has a maximum supervision capability of 10 teens XD

 

So 14 parents should be good!