You can't fit a circle with a larger radius into a smaller circle, so therefore the manhole cover can't fall in.
1
Anonymous
Jan 16, 2012
This is a well known Microsoft interview question, not for engineers but for sales people. Steve Ballmer was famous for asking this absurd question. That's why I don't think Google would ask this question.
Anonymous
Apr 11, 2011
Come on, I don't think Google asked you this question..