Letters and Envelopes Problem

There are 5 letters and 5 envelopes and for each letter there is only one right envelope present.In how many ways can one put the letters in the envelopes so that no letter is in the right envelope? I would be really glad to get a hint about its solution.

Easy Math Editor

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Comments

Hi; You want the number of derangements. This link covers it all.

link

bobbym none - 8 years ago

ya it is the no. of derangements

Sitesh Pattanaik - 7 years, 12 months ago

I think the answer is 44.

Bhargav Das - 7 years, 11 months ago

Thanks for the reply.

Sazzad Sayyed - 7 years, 11 months ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$