I ran into this question at an interview recently. The idea is more to think out loud and work out some reasonable estimates than anything else.
The question is: how many times does an average person's body rotate every day? We don't have to fix a "positive" or "negative" direction. We also don't count small rotations (less than 45 degrees). Imagine walking down a street and then making a 90 degree left. This contributes 90 degrees to our total. If, at the next intersection, we make a 90 degree right turn, this also add 90 degrees to our running count.
I was totally stumped by this question. Usually we are asked to count the number of barbers in Spain or the number of international trains passing through Berlin daily.
I first tried to split up the rotations we might make into regular and random ones. By regular I mean going to the restroom, getting to work, etc. This was very ineffective because it gives little structure to the exercise. One could easily make the case that I undercounted by a factor of 5 or 10.
Finally I was asked what sort of probability distribution would be good for modelling this. I decided that counting full rotations as discrete units, a Poisson distribution might be approriate. This was met with a frown and after some hints it became obvious that the interviewer wanted to hear the normal distribution. I would love to hear some explanation of this if anyone has an idea.