Letters and Envelopes
Probability
Level
3
In how many ways can we put 6 letters in 6 envelopes in such a manner that none of the letters are in the right envelope.
The answer is 265.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
The answer is D6 i.e.
6![(1/2!)-(1/3!)+(1/4!)-(1/5!)+(1/6!)] =265