[M] 4 hats puzzle

[SURI]

Another HAT puzzle.. provided by Rajesh

King want other variation of hat problem, so that he can kill more people.

So he invited(dragged) 4 people to death party named A, B, C and D.

A || B C D

He placed wall between A and B, so that A and B can't see. Now he placed hat on each one's head out of four hats where two are black and two are white. No one can see what hat it is on there head. In order for person to get released, they have to call out their hat color. If one of them is wrong every is dead.

who will come out securely?

[Shyam Prakash Velupula]

I think, this is a much circulated puzzle. I know the answer.
I will wait for others to solve it.

Thanks
Shyam Velupula

--
You are limited only by your imagination

[Gautham]

Can A see C and D ?
Can C and D see the all the others ?

[SURI]

Can A see C and D ?

    - No. A cant see anything. i.e. as good as blind.

Can C and D see the all the others ?

   - About B, C and D: Each can see other two hats..

Hope this clarifies.

[Thumbeti Sivaramaiah]

Lmme try this one:

The possible combinations can be (hat colors):
B || B W W
W || W B B
W || B B W
B || W W B
W || B W B
B || W B W

by seeing the above pattern, out of three guys(one side of wall) one
guy can make out his own color by seeing remaining two then shout his
color (I assuming shouting it allowed). This would be the same color
of A (then he shouts his color). based on this rest of the folks can
get to their color.

Please let me know if this looks non-sense (I will try to make it
sensible :)).

~Siva

[SURI]

Even i was thinking about the same solution.

Definately this solution makes sence to me.

-- SURI

[bhargava]

I think original problem had direction in it

A || B C D, all A,B,C,D are facing the wall, '||' being the wall.
so D can see both B,C.
C can see B
B sees nothing.

Though, it doesn't make the problem any harder

[Thumbeti Sivaramaiah]

Thanks Bhargav.

I think, now D or C can decide the color.
As D can see B and C,
if (both B and C have the same color) {
D will shout the other color;
} else {
D will keep quite. Since D did not shout so C realizes that B and C
has opposite colors. So C will shout the opposite of color of B.
}

I think original question is anyone of them must shout his/her own
color.

To extend this question, Can all of them figure out their own color???

[Shyam Prakash Velupula]

D -> C-> B || A" with this constraint

If B & C got hats of same color, then D shouts the opposite color so does A. B & C also know the color of the hats they are wearing (since D shouted)
If B & C got hats of different color, D keeps mum, C & B knows the colour of their hats (as mentioned by Sivaram). But D & A can never know for sure


- Shyam