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 7 pictures can be hanged on 9 pegs?

The number of ways in which 5 picturers can be hung from 7 picture nails on the wall is

The number of ways in which 5 picturers can be hung from 7 picture nails on the wall is

In how many ways 7 books can be arranged from 10 books?

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 can 7 athletes be chosen out of 12?