The Learning Network Blog

We have provisions in 5 hats 3 white and 2 blacks.
We lined up 3 men, each of which we put a hat chosen at random among
the 5.
They can not see his own hat, but the third sees the first two, the latter sees the former.
I ask the third man: what color is your hat, and he answers: I do not know.
I ask the second man: what color is your hat? and he answers: I do not know. I ask the first man the
same question and he answers: my hat is this color.
Question: what color is the hat of the first man and why?

Solution:

There are two blacks and three whites.
if the third saw two blacks in front of him, he would say that his hat is white, logical, but as he says:
I do not know, it means that in front of him does not see two blacks, but: 2 white, or a white and a
black or a black and a white.
the second, if he saw himself in front of a black hat, as it can not be two blacks, would say: my hat
is white; but as it says: I do not know, it means that he sees a white hat, and then the first one says:
the mine is white.
difficult, eh?