Thursday, August 11, 2011

8 women and 6 men, select PROBABILITY AND STATISTIC?

The above is a GREAT answer, except the last part you can't just consider 5 men. What you have to do is get 6 choose 3 (6 choose 3 = 6! / (3!3!) = 20), and then subtract all the combos where the 2 men are together (there are 4, because there are 4 other men who can fill the extra slot if the 2 men are together). So you get 20 - 4 = 16, not 5 choose 3 (which is 5! / 3! 2! = 10). So 16, not 10. So the final answer is 16 X 8 choose 3, or 16 X (8! / 5! 3!) = 16 X 56 = 896, so a bit more than 560.

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