Question 773706
a bag contains 4 red, 5 white and 7 black balls are taken at random,what is the probability that both of them will be black or both will be white?
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P(both black) = 7C2/16C2
P(both white) = 5C2/16C2
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P(both black or both white) = [7C2+5C2]/16C2 = 31/120
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Cheers,
Stan H.