> But "why are manhole covers round?" is not. It's a stupid "have you ever heard this clever fact" question that's often designed just to figure out if you're c

> But "why are manhole covers round?" is not. It's a stupid "have you ever heard this clever fact" question that's often designed just to figure out if you're clever and/or lucky vs testing actual knowledge and skill. I once had this interview question, gave them the expected answer, and cited the source of that answer. I never did get that job. I am going to take your claim a step further and assert that this type of question can only reliably test cleverness if the interviewee is properly primed (e.g. there was a prior discussion of workplace safety), then the important thing is explaining why. Otherwise the only way to arrive at the answer is to realize that construction/maintenance workplaces place a high priority on safety. That isn't the type of thing you're likely to think about during an interview for a programming position.