passed along from my smartest friend and his Math Teacher wife:
There are 7 girls in a bus. Each girl has 7 backpacks. In each backpack, there are 7 big cats. For every big cat, there are 7 little cats. The bus driver is not on the bus at this time.
Question: How many legs are there in the bus?
This is not a trick question (easy for him to say...), it is a real math problem, so "a bus doesn't have legs" is not any part of the answer.
When I copy/re-write anything like this, especially up on the white board in front of the class, I get OCD/paranoid I'm spelling words wrong, or omitting a word, or accidentally spelling some word I'll get calls from the parents about -- for example, do not abbreviate "after school session" !