Probability and Combinatorics

[mochaswirl]

Hello, I have a math question about probability.

The question is: A committee of five people is selected from ten females and eight males. What is the probability that there are exactly three females on the committee?

I don't think I understand how to solve this problem properly. I've tried different methods but none of them are right. Here's what I've tried so far:

10 nCr 3 / 18!

10 nCr 3 / 18 nCr 5

but after trying all these things I realized I don't understand how to get started I hope somebody can help me! Thanks in advance!

 

[pka]

The question is: A committee of five people is selected from ten females and eight males. What is the probability that there are exactly three females on the committee?

\(\displaystyle \frac{\binom{10}{3}\binom{8}{2}}{\binom{18}{5}}\)

WHY?