logical deduction - Guessing hat colors

There are 3 children sitting on three chairs. The children can only look forward and all wear one hat. The hats are either black or red. They are a total of 5 hats, 3 are colored red and 2 are colored black. The child on chair A says: "I don't know what color of the hat I have." Then the child on chair B says: "Also, I don't know the color of my hat." Then the child on chair C says: "In that case, I know the color of my hat."

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   A        B        C

The question is: What color of hat does the child on chair C have and why?

Bonus question: Do we also know the color of the hat of the child on chair A and the color of the hat on chair B?

Answer

If A doesn't know the colour of his hat, then at least one of B and C must be wearing a red hat, because if they were both wearing black, then A would know immediately that he was wearing a red one.

B knows this as well. But if C were wearing a black hat, then B would know that she was wearing a red one because of that. So since B doesn't know, C must be wearing a red hat.

C knows this as well. So C knows that his hat is red.

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As for the bonus question, no, we cannot know what colour hat either A or B is wearing. All else we can deduce from the problem is that at least one of B and C is wearing a red hat, but C wearing a red hat fulfills that already, so B could be wearing either colour of hat. And in general, nobody can know what A's hat's colour is, since nobody can see it. So all four arrangements where C wears a red hat are possible.