Vamsi Pavan’s Place

Four
men are lined up on some steps. They are all facing in the same
direction. A wall seperates the fourth man from the other three.
So to summarise :-

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
men are wearing hats. They are told that there are two white hats and
two black hats. The men initally don’t know what colour hat they are
wearing. They are told to shout out the colour of the hat that they are
wearing as soon as they know for certain what colour it is.
They are not allowed to turn round.

They are not allowed to talk to each other.

So the question is -
Who is the first person to shout out and why?

can anybody help? best of all answers comes here …