SOLUTION: A grocery store has 15 packages of shredded cheese in its dairy cooler ,3 packages are bad. Assume that packages are sold in random order. What is the probability that the first

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Question 872787: A grocery store has 15 packages of shredded cheese in its dairy cooler ,3 packages are bad. Assume that packages are sold in random order. What is the probability that the first 3 packages are all good? What is the probability that the first 3 packages are all bad? What is the probability that the third package is first bad package sold? What is the probability that exactly one of the first 3 packages is bad?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

p(bad) = 3/15 = 1/5 = .2

P(1st 3 good) = (.8)^3 = .512

P(1st 3 bad) =  (.2)^3 = .008

P(3rd is 1st bad one), 13 left(3bad), p(bad) = 3/13

P(1 out of 3 bad)= binonpdf(3, .2, 1) = .384