<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by JetTroop:
I still don't think most people would have answered truthfully because, much like me, they didn't know that they wouldn't have bothered by the search.</font>
Once again, the questions were designed to help identify an unsuspecting passenger who's checked bags contained an explosive of which he is unaware.
This isn't an unrealistic scenario, it's happened a number of times in the past.
You're right, many passengers wouldn't answer the questions truthfully but there are many who would especially if something unusual happened between the time they packed the bags and their arrival at the airport.