There are n letters and n corresponding envelopes. In how many ways the letters can be placed in the enveloped (one letters in each envelope) so that no letter is put in the right envelop.

A person writes letters to six friends and addresses the corresponding envelopes. In how many ways can be letters be placed in the envelopes so that all the letters are in the wrong envelopes.

A person writes letters to six friends and addresses the corresponding envelopes.In how many ways can the letters be placed in the envelopes so that

There are 3 letters and 3 addressed envelopes coorresponding to their . The number of ways in which the letters be placed in the envelopes so that no letter is in the right envelope is

A person writes letters to six friends and addresses the corresponding envelopes. In how many ways can the letters be placed in the envelopes so that all of them are in a wrong envelope

A person writes letters to six friends and addresses the corresponding envelopes. In how many ways can the letters be placed in the envelopes so that all of them are in a wrong envelope

A person writes letters to six friends and addresses the corresponding envelopes. In how many ways can the letters be placed in the envelopes so that all of them are in a wrong envelope

There are 5 letters and 5 directed envelopes. The number of ways in which all the letters can be put in wrong envelope is

There sre three letters asnd three envelopes. Find the total number of wys in which letters can be put into the envelopes so that each envelope has only one letter.