But the clever thing is the work required to answer these questions is a filter in itself. Firstly it filters for the seriousness of the interviewee - have they done their (days of) preparation? And even then only a few people will have he ability to actually understand the quiz questions, and even if the answers are there in front of them.
The only problem is the filter for being good at cramming interview questions is not quite congruent with the filter for being a good programmer/developer/engineer/$role_youre_hiring_for.
