# Thread: combination problem need help

1. ## combination problem need help

How do you solve part C? and How do you get 140 as the answer?

http://i41.tinypic.com/29m7zex.png

2. ## Re: combination problem need help

Originally Posted by pauly215
How do you solve part C? and How do you get 140 as the answer?
First, I have a impolite question for you: Why did you not type the out so we can easily read it?

Now I am going to play the "back-of-the-book' game with you.
$2\dbinom{8}{4}=140$.

Now you task is to explain why that works!