P(flush) = (52/52) * (12/51) * (11/50) * (10/49) * (9/48)
'cos it also = #possible flushes / number of 5-card combinations
= 52 * 12 * 11 * 10 * 9
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52 * 51 * 50 * 49 * 48
(N.B. order is important)
This is because whatever the first card is, the rest have to be the same suit.
Xtreme, what you are saying is that the origional question was asking the probability of getting a flush of a certain suit, where actually all that was said was that all the cards had to be the same suit.
