"How many gas stations in Raleigh?" I had a couple questions like this at a couple of interviews more than a few years back now. In both cases, I sat for a mi

"How many gas stations in Raleigh?" I had a couple questions like this at a couple of interviews more than a few years back now. In both cases, I sat for a minute, and asked a few questions back, like "do you mean the city limits of Raleigh, or the metro area?", "how do you define gas station - do we include public-only, or private fueling places?", etc. Part of this was buying some time, because the question caught me off guard, but I think my questions back caught him off guard a bit too. That interviewer told me I was the only person who asked clarifying questions before blurting out an answer or walk through. Another one was "take this marker and design a house on the whiteboard for me". So I took the marker and asked questions like "how many people will live here, do you want one or two story, do you need a garage/shed/basement, etc?" And again, was told I was the only person who'd asked questions before starting to draw. I don't think the intention behind those brain teasers was necessarily to determine how you react to those sorts of problems, but it may have been a useful determining factor for some interviewers nonetheless.