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A bag has 3 white, 2 black, and 4 red balls. Four balls are selected at random with replacement. What is the probability that exactly one of the four balls drawn is white?
- 16/81
- 8/81
- 32/81
- 4/81
Correct answer: 32/81
Solution
P(white)=3/9=1/3 each draw (with replacement). P(exactly one white in 4) = C(4,1)(1/3)(2/3)^3 = 4*8/81 = 32/81.
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