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Old 07-25-2005, 07:24 PM
Homer Homer is offline
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Join Date: Sep 2002
Posts: 5,909
Default Re: Red / Black Cards. Puzzle

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This surprised me.

A single red card is removed from a standard 52 card deck. Then 13 cards are drawn and found to be the same color. What is the probability that they are black?

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<font color="white">I should be able to do this one!

Number of ways to get 13 consecutive red = C(25,13) = 5200300

Number of ways to get 13 consecutive black = C(26,13) = 10400600

P(black) = 10400600 / (5200300 + 10400600) = 2/3</font>
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