Question 1099269
<br>The problem is to pick socks so that you know for sure that you have 5 pairs.<br>
To answer a question like that, you need to use the "worst case" scenario.  The worst thing that can happen is that the first 8 socks are all different colors.  In that case the next 5 picks will create 5 pairs.<br>
So the number of socks he needs to pull out of the drawer to guarantee having 5 pairs is 13.