A servant has to post 5 letters and there are 4 letter boxes. In how many waysy can he post the letters?

5 letters can be posted into 3 letter boxes in:

In how many ways can 4 letters be posted in 5 letter boxes?

In how many ways can 5 letters be posted in 4 letter boxes?

In how many ways can 4 letters be posted in 5 letter boxes?

In how many ways can 4 letters be posted in 3 letter boxes?

In how many ways can 7 letters be posted in 4 letter boxes?

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

Suppose 4 letters are taken out of 4 different envelopes. In how many ways, can they be reinserted in the envelopes so that no letter goes in to its original envelope?

For the post of 5 teachers, there are 23 applicants, 2 posts are reserved for SC candidates and there are 7 SC candidates among the applicants. In how many ways can he selection be made?

Three letters can be posted in five letter boxes in 3^(5) ways.