SOLUTION: A bag contains 20 tennis balls, of which four are defective. If two balls are selected at
random from the bag, what is the probability that both are defective?
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-> SOLUTION: A bag contains 20 tennis balls, of which four are defective. If two balls are selected at
random from the bag, what is the probability that both are defective?
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Question 1113562: A bag contains 20 tennis balls, of which four are defective. If two balls are selected at
random from the bag, what is the probability that both are defective? Answer by math_helper(2461) (Show Source):
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P(both are defective) = P(1st is defective)*P(2nd is also defective)
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Assuming the selections are made without replacement:
P(both are defective) = (4/20)(3/19) = 12/380 = or approx 0.03158.
