[Ulrike]

Here's my favorite riddle of all time:

"Census guy: How many kids do you have?
Father: 3 daughters.
Census guy: What are their ages?
Father: If you multiply their ages together, you get 36.
Census guy: O....k?
Father: I'll give you another hint. If you add their ages together it equals the house number across the street.
Census guy: ...........?!?!
Father: Ok last hint. My oldest daughter plays the piano.

Figure out the ages of the 3 daughters."