Please don't propagate the myth that Google asks prospective programmers questions like, "How many golf balls could you fit on a bus?" Google interviewers list the questions they asked when they write up their conclusions, and anyone who asked a question like that for an engineering interview would be immediately contacted by the hiring commitee and told not to do it again.
Truthfully, for a kid coming straight out of college, that's not such a terrible question to ask. (No, I didn't get the job. :P) It allows you to start from a totally neutral knowledge position, and lets you see how a person thinks critically about an unorthodox problem - one they almost certainly haven't seen before.
The problem comes when kids start training for such problems, instead of just tackling the sorts of interesting challenges that would inadvertently cause them to approach this question well...