One classic funny quiz questions is: What is an example of a non-vulgar four-letter word ending in "k" that means "intercourse?" The answer: Talk. The humour in this question lies in the fact that another word immediately springs to mind; much of the power of humor comes from setting up expectations and then subverting them.
More examples of this nature are: If you order a Bombay Duck at a restaurant, what will the waiter bring you? Answer: Fish. (There are many competing theories about why this species of fish has such a misleading name.) When signing up for an online bank, what would astronaut Buzz Aldrin put as his mother's maiden name: Moon. (That was really her maiden name, and Aldrin was the second man to set foot on the moon.)
How many man-made structures can be seen from space? Answer: None. (The Great Wall of China is long enough, but it is far too narrow to be seen from space.) What kind of animal were the Canary Islands named after? Answer: Dogs (Canary dogs, to be precise). What is Scooby-Doo's full first name? Scoobert. Finally, what cartoon character's nephews are named Peepeye, Pupeye, Pipeye and Poopeye? Ask this one after your guests have gotten used to the obvious answer never being the correct one, because in this case the answer is Popeye.