1. The problem statement, all variables and given/known data I have this problem that says that i have 30 pair of socks mixed in a box, and i have to make 10 pairs taking them one by one of the box. The question is "¿Wich is the most probable number of tries that you'll make before you get the 10 pairs? (Sorry for my english, i'm not from a native english speaker country) 2. Relevant equations I know it has something to do with the Gauss distribution, but that's it, my probability teacher is an A-hole. 3. The attempt at a solution By doing a program in php that simulates the experiment, i get that the center of the gauss function graphic is 28 or 29.