There are one red card and two black cards.
I pass these three cards to Taro, Jiro, and Hanako.
They look at the color of their own and find the color of the card of other two.
I asked Taro but Taro said "I can not find."
Jiro heard the answer of Taro then said "I can guess by hearing the answer of Taro."
What color is a color of three cards of three persons?
I pass these three cards to Taro, Jiro, and Hanako.
They look at the color of their own and find the color of the card of other two.
I asked Taro but Taro said "I can not find."
Jiro heard the answer of Taro then said "I can guess by hearing the answer of Taro."
What color is a color of three cards of three persons?
Answer
But since Taro answered "I can not find", the color of Taro turns out to be black.
Since Jiro heard the answer of Taro and found the color of other cards of two persons, it turns out that Jiro has also black.
Therefore, Taro has black, Jiro has black and Hanako has red.
Taro has black, Jiro has black, and Hanako has red.
Solution
If Taro had red, Taro could find the color of other cards of two persons.
But since Taro answered "I can not find", the color of Taro turns out to be black.
Since Jiro heard the answer of Taro and found the color of other cards of two persons, it turns out that Jiro has also black.
Therefore, Taro has black, Jiro has black and Hanako has red.
