Three persons

Question:

This question tests your coherent conjecture and deductions. Close your eyes, imagine the situation, step into the shoes of each of the three persons, and draw conclusions to find the correct solution to save the life of the three: A, B, C are captured by cannibals in a jungle. The men are given one chance to escape with their lives. The men are buried one after other (<<<) in such a way that the last man (C) can see the backs of the front two, the middle man (B) can see the back of the front man (A) and the front man (A) can’t see anybody. The men are shown four hats, two black and two white. One hat is placed on each man’s head and the fourth hat is thrown away. The men are told that if at least one of them can guess the colour of his hat, they can all go free. Time passes. Finally, the middle man correctly guesses the colour of his hat. How does B guess it correctly?

.

.

C

A

P

T

A

I

N

I

N

T

E

R

V

I

E

W

.

.

Solution: This is to be worked in three steps. 1. According to the question, there are two white and two black hats. C can see the hats of the two men in front of him. So, if 2 front hats are white, he would automatically know that his hat is “black”. If the front 2 hats are black, he would immediately shout that his hat is “white”. But, since he doesn’t say anything, he inevitably must be seeing one black hat and one white hat ahead of him. 2. After it becomes clear to B that the man behind him can’t figure out what he’s wearing, he knows that there is one black hat and one white hat worn by himself and the other person in front man A. Knowing this, if the middleman saw a white hat before him, he tells that his own hat was black or vice versa. He tells the cannibals exactly the same. Thus all three people escaped death.

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