I'll be impressed if anyone can get this. I sure can't: There are 12 identical looking stones. Inside one of the stones is a diamond that you want to find. 11 of the stones weigh exactly the same, and the one with the diamond weighs either slightly more or slightly less than the others. You are given three balance scales (like the kind that Lady Justice holds), and you may only use each scale once. When using the scales, you may NOT put one stone on at a time, or put a bunch on and then remove stones one at a time. So, how do you find the stone with the diamond, and how do you determine that it is lighter or heavier than the other 11.