Quote Originally Posted by Demiparadigm
If you have 2 different cards, to get trips we determine the chance of pairing one of our cards on the first card (6 cards will give us a pair) and multiply that to the chance of a card of the same value coming in the next 2 cards:
(6/50)*[1- (47/49)*(46/48)]= 0.00972
As was pointed out, this calculation is slightly in error since it rules out the possibillity that the second and third flop cards pair the "other" hole card.

Note that it doesn't rule out flopping quads, though your next calculation does.