Question 190152
you are taking a test that contains 5 multiple choice questions with 4 possible answers. you guess at all questions. find the probability that you guess exactly 2 questions 
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Binomial problem with n=5, p = 1/4, x = 2
P(x=2) = 5C2(1/4)^2(3/4)^3 = 10*(27/4^5) = 0.2637
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Cheers,
Stan H.