Homework Time!

I started working on the next section of homework and it was MUCH more confusing for me than the first one was! 

I got stuck on the first question and couldn't seem to figure it out! On the online homework we have an option called "help me solve this" it takes you through the homework step-by-step and shows you what to do. So, I figured after doing that I should be able to get it right? Wrong! I was still confused. 

Here's what the problem was that got me: 

A box contains 7 yellow balls and 5 red balls. Two balls are drawn at random from the box. 

a) If the first ball is drawn and not replaced, the probability that two balls will be drawn of different colors is what?

As I was trying to figure this out I remembered that we had done a similar problem in class. So, I pulled out my worksheet from class, looked that and my notes over and was able to solve the problem!! The paper from class was much less confusing than what the computer was trying to tell me! 

This is how I solved it: