Why? I'm curious because sometimes I use a "trick" question (trick in quotes because this really isn't a trick question either) to gauge someone's ability to th

Why? I'm curious because sometimes I use a "trick" question (trick in quotes because this really isn't a trick question either) to gauge someone's ability to think on their feet. A "trick" question being one I'm fairly certain there's no answer to floating around and which requires some thinking. The goal should never be a pass/fail did they know the trick question, but someone who can think on their feet and work through one is more appealing to me than someone who throws in the towel.