This is rumored to be an interview question - for it you should imagine that you are in an interview booth, a room that usually fits just two people and a desk, about six feet by six feet
Say you have a stack of pennies that were as tall as the Sears Tower (stacked horizontally, like in a roll of pennies, and not stacked standing on their edges). Would you be able to fit all of those pennies in this room?
Try to come up with an answer as quickly as possible, without measuring pennies or writing down any equations.