A small one..
Three masters of logic wanted to find out who was the wisest one. So they invited the grand master, who took them into a dark room and said: “I will paint each one of you a red or a blue dot on your forehead. When you walk out and you see at least one red point, raise your hands. The one who says what color is the dot on his own forehead first, wins.” Then he painted only red dots on every one. When they went out everybody had their hands up and after a while one of them said: “I have a red dot on my head.”
How could he be so sure?
March 4, 2008 at 4:25 am
If all of them had blue dots on forehead, none of them would have raised hands.
If two of them had blue dots on forehead, the other one would not have raised his hand.
But all the three raised hands, which means either only one of them had a blue dot or all of them had red dots.
The logic master who answered would have reasoned out like this -
I can see two red dots. So I can either be having a red dot or a blue dot.
“If I had a blue dot on my forehead, the other two could have answered immediately as they can see a blue dot and a red dot on the other two foreheads. Both of them have raised hands which means that both of them must be having red dots on their foreheads. They would have reasoned it out and answered.
Since both of them didnot answer for sometime, I donot have a blue dot on my forehead. It must be a red dot.”
March 19, 2008 at 6:16 am
I agree with Sreelu… but I should say…. really nice one…