AOG's post reminds me of a situation at work many years ago when we were having a security door installed which was to only let one person at a time through it; this was done by having a floor which weighed the occupant before allowing them through. This required the man setting up the door to know the weight of anyone likely to use it. Appreciating that he would get short change from many people if he asked their weight he came up with a cunning plan; he would say to someone "you look a bit hefty, you must weigh at least 12 stones", to which they would reply "Cheeky monkey, I only weigh 10 stone 3". Problem solved.