5 hats, 2 hats remained unused). There is no light in the tent and there is no way the scientists can see or figure out which hat is which.
He told the scientists that they have to walk out of the tent in a queue, and then any one of them has to guess the colour of the hat on top of HIS head. They are to stand so that the third scientist can see the colour of the hats on the two scientists in front of him. The middle one can only see the colour of the hat on the scientist in front of him. The first scientist cannot see anyone's hat. The scientists were given 10 minutes inside the tent to discuss their strategy. Once they walk out, the only thing any one of them is allowed to say is "The colour of my hat is ..........". If the colour is correct they will all be set free. If the colour is wrong or anyone says or does anything else, all of them will be cooked and eaten!
The scientists went out, they stood there for some time, and then one of them said "The colour of my hat is ........!". What colour was his hat?