In cribbage 6 cards are initially dealt from a standard deck. one of the ways to get points is to have a "15", i.e. having a set of 4 or fewer cards whose sum is 15 (j,q,ks all count as 10, a counts as 1, and 2-10 count as their number.) what is the probability of getting exactly 1 "15"? (note 5,10,10,3,3,8 counts as 2 "15"s since the 5 and the first 10 and the 5 and the second 10 both give 15, but 5,5,5,6,7 only counts as 1 "15"–all three 5s together.)
