October 26, 2012 2 Comments
The new toy craze is Mega Men, where kids buy a Mega Man in a box. The box won’t tell you which one it is, and kids open it up when they get home in hopes of getting one they don’t already have. (Sadly, eBay is not an option, since the only cool Mega Men are the ones still in their original packaging.)
There are ten toys in all, each equally likely when you buy a box. If you collect all ten, you can make Super Ultra Mega Man!
On average, how many Mega Men will you have to buy for your kid before he can finally collect them all?
(Stolen from PCMI 2007 Day 1 Problem #11: http://mathforum.org/pcmi/hstp/sum2007/morning/bowen/day1handout.pdf)