2015 AIME I Problems/Problem 5
Problem
In a drawer Sandy has 
pairs of socks, each pair a different color. On Monday Sandy selects two individual socks at random from the 
socks in the drawer. On Tuesday Sandy selects 
of the remaining 
socks at random and on Wednesday two of the remaining 
socks at random. The probability that Wednesday is the first day Sandy selects matching socks is 
, where 
and 
are relatively prime positive integers, Find 
.
