SOLUTION: There are 7 red and 4 white discs in a bag. A disc is drawn, then replaced and another disc is drawn find the probability that both discs are the same colour.

Question 1037894: There are 7 red and 4 white discs in a bag. A disc is drawn, then replaced and another disc is drawn find the probability that both discs are the same colour.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
There are 7 red and 4 white discs in a bag. A disc is drawn, then replaced and another disc is drawn find the probability that both discs are the same colour.
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# of same-color pairs:: 7C2 + 4C2 = 21+6 = 27
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# of random pairs:: 11C2 = 55
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P(select same color pair) = 27/55
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Cheers,
Stan H.
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