Question 314759
After studying all night for a final exam, a bleary-eyed student randomly grabs 2 socks from a drawer containing 9 black, 6 brown and 2 blue socks, all mixed together.  What is the probability that she grabs a matched pair?
<pre><b>
She can grab two black socks any of 9C2 or 36 ways.
She can grab two brown socks any of 15 ways.
She can grab two blue socks 2C2 or 1 way.

So she can be successful in 36+15+1 or 52 ways

She can pick any two socks 17C2 or 136 ways.

The desired probability is {{{52/136}}}, or {{{13/34}}}.

Edwin</pre>