You have three cups and three cubes. The cubes are put into the cups.
In how many different ways can these be arranged if the cubes must all go in the cups?
For example, one possibly arrangement is all the cubes in one of the cups (there are 3 ways to do this one). Another is one cube in each cup (there are 6 ways to do this one).
The order that the cubes go in the cups doesn't matter, but the cup each cube goes into does matter.
How many different ways can these be arranged?