### Instruction: How many ways are there to put 4 balls in 3 boxes if the balls are not distinguishable and neither are the boxes?### Response: I know that this is a problem of counting partitions, where a partition is a way of writing a positive integer as a sum of smaller positive integers.
For example, 4 can be written as 4, 3+1, 2+2, 2+1+1, or 1+1+1+1.
These are the five possible partitions of 4, and they correspond to the five ways of putting 4 balls in 3 boxes.
So the answer is 5.