Which sentence contains a pun?

1. Can we get together on this tomorrow?
2. But that shirt is missing sleeves!
3. Would a cardboard belt be a waist of paper?
4. I blinked at the bright light outside.

1 answer

The sentence that contains a pun is: 3. Would a cardboard belt be a waist of paper?

The pun here is on the word "waist," which sounds like "waste," creating a play on words.