The probability of a defect of a collection of bolts is 5% if a man picks bolts what is the probability that he does not pick 2 defective bolts.
Please help to solved the problem thank you very much
Please help to solved the problem thank you very much
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You may have left something out of the question. Like maybe it should say "if a man picks ten bolts, what is the probability that he did not pick exactly two defective bolts ? "
Or maybe you mean if he picks two bolts, what is the probability that he did not pick two defective bolts.
If he picks one bolt. there is a 5% chance that it is defective, and a 95% chance that it is not defective.
If he picks two bolts, there is a .05 * .05 = .0025 chance that both are defective (or 0.25%)
and there is a .95 * .95 = .9025 chance that neither is defective;
and the remainder ( 1 - .0025 - .9025 = .095) chance that one is defective and one is not.
Or maybe you mean if he picks two bolts, what is the probability that he did not pick two defective bolts.
If he picks one bolt. there is a 5% chance that it is defective, and a 95% chance that it is not defective.
If he picks two bolts, there is a .05 * .05 = .0025 chance that both are defective (or 0.25%)
and there is a .95 * .95 = .9025 chance that neither is defective;
and the remainder ( 1 - .0025 - .9025 = .095) chance that one is defective and one is not.