Square Playground Equipment: Playground dare with their parents, the children play together

Square Playground Equipment: Playground dare with their parents, the children play together

A group of people having a party, each person's head wearing a hat. Hat simply wrong two kinds, at least one black. Everyone else can see the color of the hat, but can not see their own. Moderator to let everyone see what others are wearing a hat, and then turn off the lights, if someone thought he was wearing a black hat, slap yourself in the face. First turn off the lights, no sound. So turn on the lights again, we see it again, when the lights are still silence. Until the third turn off the lights, only the sound of crackling slapping sounds. Q. How many people wearing the black hat?

Options: A.2 B.3 C.6 D.10 answer analysis:

Assuming that only one person wearing a black hat, he saw everyone wearing a white hat, first turn off the lights when you shall slapping, so it should be more than one person wearing a black hat; if there are two black hat, both for the first time only to see the other side of the black hat head, not sure of the color of their own, but the second the light on, it should be understood that the two men, wearing the white hat if his own, and that the other party as early as the last time it should be slapping, so is wearing his black hat, so there will be a slap in the face rang; the fact is the third time it sounded a slap sound, indicating the audience more than two black hat, and so on, should be off a few lights back there a few black top hat. Answer: B