Here's a brain challenge.  There is a right answer and a wrong answer.  In my experience, bright people arrive at both answers, and tend to dig in ferociously and start yelling.  So here it is - remember to be nice and not yell at people - first person to use all caps loses. An airplane sitting on a conveyor belt.  The airplane has either propellers or jet engines - it doesn't matter.  The airplane's wheels are just wheels - no brakes or motors on the wheels at all. For purposes of thi