You have four addressed letters and four addressed envelopes. If you close your eyes and randomly insert letters into envelopes, what is the probability that exactly three letters will be in the right envelopes?

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Originally posted by THUDandBLUNDER
You have four addressed letters and four addressed envelopes. If you close your eyes and randomly insert letters into envelopes, what is the probability that exactly three letters will be in the right envelopes?

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Originally posted by bbarr
1/4 X 1/3 X 1/2 = 1/24

Originally posted by THUDandBLUNDER
Nope.

Originally posted by bbarr
Tricky. The probability is 0. If three are correct then the fourth must be also. Of course, the probability I gave above was for randomly placing all four envelopes correctly.

Im pretty sure it's not zero, because it is possible for it to happen. I can't remember the equation off hand, but it's not quite 4! - I'll consult my communications book -

what if i stuffed 3 letters in the correct envelopes and then stuffed the extra letter with another letter leaving an envelop empty then there could be 3 correct and 1 false

Originally posted by Otis
what if i stuffed 3 letters in the correct envelopes and then stuffed the extra letter with another letter leaving an envelop empty then there could be 3 correct and 1 false

0 because you have no hands duh

well if you only stuff 3 of the envelopes with letters, then what is the probability?

Originally posted by Awry
well if you only stuff 3 of the envelopes with letters, then what is the probability?