SOLUTION: A sample of 4 different calculators is randomly selected from a group containing 18 that are defective and 40 that have no defects. What is the probability that at least one of the

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Question 1204335: A sample of 4 different calculators is randomly selected from a group containing 18 that are defective and 40 that have no defects. What is the probability that at least one of the calculators is defective?
Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
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The total set is 40 + 18 = 58 calculators.


The probability that no one of 4 calculators is defective is

    %2840%2F58%29%2A%2839%2F57%29%2A%2838%2F56%29%2A%2837%2F55%29 = 0.215405284.



The probability that at least one calculator is defective is the complement to it

    P = 1 - %2840%2F58%29%2A%2839%2F57%29%2A%2838%2F56%29%2A%2837%2F55%29 = 1 - 0.215405284 = 0.784594716.


ANSWER.  The probability that at least one calculator is defective is  0.7846  (rounded).

Solved.