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Posted by Jill on Tuesday, January 25, 2011 at 11:15am.

There are 7 rap songs, 7 rock songs and 5 classical songs to select from. Three songs are to be chosento play at random -what is the probability that only classical songs are selected? -what is the expected number of classical songs to be selected?

number of all possible triples selected = C(19,3) = 969 number with exactly one classical, 2 from the others = C(5,1)xC(14,2) = 5(91) = 455 prob of your event = 455/969

don't understand your answer Reiny

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