(puzzle) Scarf color

Topic:

There are five scarves, three Bai, there are three people in a row, each wearing a turban, the back of the person can see the front of the person's turban color, let everyone guess the color of their hijab, the first person said do not know, the second person said do not know, the third person said do not know, silence a while, suddenly someone said "I know", Which one is this person, please? What color is his turban?

Ideas:

Answer:

The first one, the turban is white.

Analysis:

In the beginning, the first person does not know anything, the second everyone knows the first person's turban color, the third person knows the first two person's turban color;

Then three people said do not know, it is clear that the first person must not know at the beginning, the second person can not know, but the third person said do not know, the front two person's turban is not red, if all is red, then the third person must be white.

Second, after listening to a round of statements, the front two people's turban color may be red white, white red, in vain, at this time the second person can not judge their own scarf color, indicating the first person's turban is white, because if it is red, then the second person is white;

Finally, since the second person cannot judge the color of his scarf, the first person can be sure that his turban is white.

(puzzle) Scarf color