<PRE><B>Question 724259</B>
Three screws are drawn at random from a lot of 100 screws, 10 of which are defective. Find the probability of an event that all three screws drawn are non defective, assuming that we draw 
a) with replacement
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Binomial problem with n = 3 ; p(defect) = 0.1 ; p(not defect) = 0.9
P(3 not defective) = 0.9^3 = 0.729
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(b) without replacement
# of ways to succeed: 90C3
# of possible outcomes: 100C3
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P(3 not defective) = 90C3/100C3 = 0.7265
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Cheers,
Stan H.
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