Wednesday, July 20, 2011

4 Criminals Puzzle

4 criminals are caught and are to be punished. The Judge allows them to be freed if they can solve a puzzle. If they do not, they will be hung. They agreed.

The 4 criminals are lined up on some steps (shown in picture). They are all facing in the same direction. A wall separates the fourth man from the other three.

So to summarize:

Man 1 can see men 2 and 3.
Man 2 can see man 3.
Man 3 can see none of the others.
Man 4 can see none of the others.

The criminals are wearing hats. They are told that there are two white hats and two black hats. The men initially don't know what color hat they are wearing. They are told to shout out the color of the hat that they are wearing as soon as they know for certain what color it is.

They are not allowed to turn round or move.
They are not allowed to talk to each other.
They are not allowed to take their hats off.

Who is the first person to shout out and why?


If both Man 2, Man 3 have same hat color. Man 1 shouts opposite color to that of Man 2 and Man 3.

If Man 2, Man 3 have different hat color. Man 1 is quiet. So Man 2, shouts opposite color to that of Man 3!


Plato said...

That was brilliant! :)

Anonymous said...

How do we know that whether 1 has shouted or not

prince said...

Man 2 is first to shout...,coz man 1 stood silent...which indicated man 2 that man one is wearing black color had man 2 b wearing black.,man 1 was first to shout...

abhijit said...

Why shud man 2 shout opposite color. The puzzle doesnot mention that they have to be alternate color.

Deepak said...

It's because one was confused as both have alternate color!

Anonymous said...

This will save 2 and 3! What about 1 and 4? How will they figure out their hat colors when 2 & 3 have diff colors?