I used to work for a company, when the supervisor interviewed people, he would ask a whole bunch of technical question about the database.  Then he would ask a IQ question - liked why was the pothole round not square?  I never understood why.  However when he interviewed me, he forgot to me the IQ question, otherwise I would never get the job. Actually I did not know if it was good or bad, I ended up working for that company for 8 months.

IQ question - actually this was from Bill Gates, he said if anyone could answer this question in 5 minutes, then the person was capable working for him, otherwise, forget it.  I could not answer this question so I could never work for Microsoft !   My eight years old son answered this question correctly but it took him half a day.

There are two rooms seperated by a wall.  One room has 3 switch, one room has three lamp.  How can you tell which switch belong to which lamp?  You can only go to look at the room once.