Played along, did not take much to quench their thirst for testing my knowledge. I did answer something they didn't seem to like, which is how useful a burndown chart (or burn up) is to a project manager. They were surprised, probably wanting something more in respect to profitability, risk management, and many others. I live by my experience thou as more of those other aspects doesn't matter that much if you are right in scope and time, which the burndown gives you if everything else is considered managed.