There are 4 letters and 4 addressed envelopes. Find the probability that all the letters are not dispatched in right envelopes.

Explanation

Given,

There are 4 letters and 4 envelopes with address


The probability that the letter goes into the right envelope = `¼!`

The probability that the letter does not go into concerning paper envelopes

= `1-` the probability that the letter goes into the right envelope.

`= 1- (¼!)`

`= (4! -1)/4!`

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