Three men were on board an airplane flying over an ocean, suddenly Death appears on the plane. He turns to them and says, “Before I take you all with me I will give you each an opportunity to survive. In turn each of you will throw something into the ocean and if I can find it you will die, if not you may continue to live”.
The first one throws a button. Death goes down to the ocean searching for it. After a couple of minutes he comes back with the button.
The second one throws a hair. Death goes down and after several minutes he comes back with the hair.
The third one quickly throws something and Death goes down again, about an hour later he comes back and says to the guy “Ok I give up, you win. I’ll let you live, but tell me what did you throw?”
The guy says “A soluble tablet”