SOLUTION: A box contains 5 brown and 4 white socks. A man takes out two socks. The probability that they are of the same color is:

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Question 475972: A box contains 5 brown and 4 white socks. A man takes out two socks. The probability that they are of the same color is:
Found 2 solutions by stanbon, Edwin McCravy:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A box contains 5 brown and 4 white socks. A man takes out two socks. The probability that they are of the same color is:
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P(2 brown or 2 white) = P(2brown) + P(2white)
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= 5c2/9C2 + 4C2/9C2
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= (10 + 6)/36
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= 4/9
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Cheers,
Stan H.
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Answer by Edwin McCravy(20064) About Me  (Show Source):
You can put this solution on YOUR website!
A box contains 5 brown and 4 white socks. A man takes out two socks. The probability that they are of the same color is:
P(1st brown AND 2nd brown) OR P(1st white AND 2nd white) =

and since AND is a clue to multiply and OR is a clue to add,

P(1st brown)×P(2nd brown) + P(1st white)×P(2nd white) =

P(1st brown) = 5/9
P(2nd brown, when 1st was brown) = 4/8 
P(1st white) = 4/9
P(2nd white, when 1st was white) = 3/8

P(1st brown)×P(2nd brown) + P(1st white)×P(2nd white) =

            (5/9)(4/8) + (4/9)(3/8)


                  20/72 + 12/72

                     32/72

                      4/9

Edwin