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combinations and permutations

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by DanaJ » Wed Mar 04, 2009 9:49 pm
I can't see the whole thing because of the messages from the community sponsors, but I suppose they're asking for the number of 4-person committees out of a 10-person pool. This is going to be 10C4 = 210. This is a problem involving combinations. What you calculated is an arrangement, a case when the order of the objects (in this case, committee members) counts. With combinations, the order is not relevant (i.e. abcd is the same as dcba).
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Whats the OA?

by Dream Weaver » Wed Mar 04, 2009 9:51 pm
IMO, it should be 210.
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by mkbigmoz » Wed Mar 04, 2009 10:50 pm
10!/4!(10-4)! = 210
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by coolgirl26 » Wed Mar 04, 2009 11:30 pm
thank you that helps
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