In how many ways 4 paintings Can be hung on 4 walls of a room so that any number of paintings Can be hung on any wall

In how many ways 7 pictures can be hung from 5 picture nails on a wall?

In how many ways 7 pictures can be hung from 5 picture nails on a wall?

In how many ways can 6 pictures be hung from 4 picture nails on a wall?

In how many ways can 5 balls be placed in 4 tins of any number of balls can be placed in any tin ?

In how many ways can 5 prizes be awarded to 4 boys if each boy is eligible for any number of prizes?

In how many ways can 3 letter boxes when each box can take any number of letters?

In how many ways 4 persons can be arranged in 3 rows with out any restriction. If each row can accommodate any number of persons.

In how many ways can 5 prizes be distributed to 8 students if each student can get any number of prizes?