PUZZLES

[sgokulprathap]

Please post some interesting puzzles in this thread and let other hubbers find the answer by their intelligent brain.

Let me begin with a puzzle:

Three Gentlemen

There are three men standing in a row. All are wearing hats. The hats were chosen from a set of three black and two white hats. Nobody knows which color he himself is wearing. But the man at the back knows the colors of other men's hats and the man in the middle knows the color of first man's hat.
The last man was asked whether he knew the color of his own hat. "No",he said.
The man in the middle was asked the same question and he too said,"No."
Now the first man was asked the same question and he said,"Yes,I know."
Did he really know? If yes, what was the color? and how did he arrive at the answer?