This problem has been solved successfully from the top weighting master Frank Entrich from Norderstedt (Germany) on August 9th, 1996, so the price has already been awarded. But you can still puzzle this problem for yourself or inside your circle of friends, the answer can be called here directly.
There are twelve spheres in front of yourself which all have exactly the same appearance:
But one of these twelve spheres has a different weight:
Your available measuring tool is only a simple beam balance:
Your task: Find out with only three weight measures the differing sphere and try to guess, if it has more or less weight than the other eleven spheres at the same time! Important: Please consider all cases! Have a lot of pleasure while puzzling! Pay attention that your head doesn't start to smoke or a load of full-doodled notepad sheets around your bed begins to cause in your bedroom!