I'm looking for good analytical/math problems...

We're searching for some test questions to give college seniors who might be interested in working at our office here. Any suggestions?

Things like "Create the number 24 using only these numbers once each: 3, 3, 7, 7. You may use only the following functions: +, -, *, /. This is not a trick question, for example the answer does not involve a number system other than base 10 and does not allow for decimal points."

Would be great.

Basically we're looking for word and/or graphic problems that should be reasonably challenging.

Just e-mail me any suggestions you have in the next 24 hours :-).

Thanks!