I do agree that logic puzzles which require a single observation and/or have a binary outcome tend to be very bad interview questions. That being said, I think

I do agree that logic puzzles which require a single observation and/or have a binary outcome tend to be very bad interview questions. That being said, I think the original post demonstrates that the issue with the manhole cover problem isn't necessarily the question itself, but how it's evaluated. I'd be quite pleased if I were asking the question and the interviewee gave that answer (though I might raise the point that the configuration necessary to drop a rectangular cover is also one of the most ergonomic for holding it). The general notion that there is a single right and wrong answer is incongruous with a class of question used to evaluate the candidate's reasoning ability. Though I wouldn't be surprised if these were historically evaluated appropriately and candidates simply misinferred why they were being rejected.