In packing for a trip, Sarah puts three pairs of socks - one red, one blue, and one green - into one compartment of her suitcase. If she then pulls four individual socks out of the suitcase, simultaneously and at random, what is the probability that she pulls out exactly two matching pairs?	Choose the correct choice from the following choices.
A) 1/5  B) 1/4  C) 1/3  D) 2/3  E) 4/5
the successful events are when Sarah pulls 2 matching pair of socks out of 3 matching pairs of socks, which can be done in 3C2 ways as the order is not important   So,3C2 = 3 ways are:   RRBB   RRGG   BBGG   Now,the ways in which 4 socks can be pulled out of 6 socks (3 pairs) = 6C4 = 15   So, probability = 3/15 = 1/5   1/5ns: 1/5
<result>A</result>
In packing for a trip, Sarah puts three pairs of socks - one red, one blue, and one green - into one compartment of her suitcase. If she then pulls four individual socks out of the suitcase, simultaneously and at random, what is the probability that she pulls out exactly two matching pairs?