Its not hard but sometimes tedious.


Let's say you want the probabillity of a flush if you hold Ah 7h.


SO P(flush)= P(3 hearts on the board)


+ P(4 hearts on the board)


+P(5 hearts on the board)


= {11C3 (39 C2) + 11C4 (39) + 11C5}/50C5.