Generate a joke that its punchline involves the phrase "bar of soap".
Why was the math book sad?

Because it had too many problems, but a bar of soap won't be able to help!
Complete the following task based on the instruction and optional input provided.### Instruction:
Generate a joke that its punchline involves the phrase "bar of soap".

### Output:
Why was the math book sad?

Because it had too many problems, but a bar of soap won't be able to help!