When we write |*X*|=*m*, we mean that *X* is a finite set that contains
exactly *m* elements; i.e., the cardinality of *X* is *m*.

- If |
*X*|=*m*and |*Y*|=*n*, how many relations between*X*and*Y*are there? - If |
*X*|=*m*and |*Y*|=*n*, how many functions are there? - Suppose |
*X*|=*m*, |*Y*|=*n*, and is a function. Try to fill in the following table by giving a formula for the number of functions in each case: - How many ways are there of removing a regular tetrahedron from the table and replacing it in the same position, but not necessarily with the same sides facing the same directions as before?
- How many ways are there of removing a cube from the table and replacing it in the same position, but not necessarily with the same sides facing the same directions as before?

Wed Sep 30 08:36:10 EDT 1998