I would love to understand how to solve this problem: Robby doesn't like the color brown and will not eat the brown M&M's.  On his first bag, he sets aside  9 brown M&M's.  On the second bag, he sets aside 12.  On his third & fourth bag, there are 8 brown M&M's that he doesn't eat. On his fifth bag, there are only 3 brown M&M's that he doesn't eat.  What's the average number of brown M&M's in a bag?
Can you explain?