<PRE><B>Question 696875</B>
a secretary types 5 letters and 5 envelopes puts the letters into the envelops at random.what is the probability that at least 1 letter is put into its correct envelope
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P(at least one correct) = 1 - p(all incorrect)
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P(all incorrect) = 1/2^5 = 1/32
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P(at least one correct) = 1 - 1/32 = 31/32
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Cheers,
Stan H.
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