[LetYouDown]

Someone correct me if I'm wrong.

Say one player holds 5-5 the other 10-10. The probability of the flop coming 5-10-X where X is not a 5 or a 10:

(C(3,1) * C(3,1) * C(44,1))/C(48,3)

396/17296 = 2.29%

Say one player holds 5-5, another 10-10 and another Q-Q. The probability that 2/3 will flop a set is:

5-10-X where X is not a 5, 10 or Q = (C(3,1) * C(3,1) * C(40,1))/C(46,3) = 360/15180 = 2.372%
5-Q-X where X is not a 5, 10 or Q = 2.372%
10-Q-X where X is not a 5, 10 or Q = 2.372%

So for 2 out of 3 flopping a set, I get 1080/15180 or about 7.11%.

For all three flopping a set, I get 27/C(46,3) or .178%