Probability check-up

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Re: Probability check-up

by gabriel » Mon Jul 23, 2007 10:33 am
Anonymous wrote:I wrote down this problem, but forgot to write down the answer.

5 apples and 1 of them is spoiled. If two apples are pulled out, what is the probability that one of them will be spoiled?

I solved it like this:

The prob(no spoils) = 4/5*3/4 = 12/20 = 3/5

1 - prob(no spoils) = at least one spoil = 1 - 3/5 = 2/5

Does anyone else get 2/5 as the correct answer?

Thanks!
.. 4c1/5c2 = 2/5 ..