Hat problem

The answer is: the boss standing in front is wearing a white hat.

Explanation: The boss assumes that he is wearing a red hat, so the second child standing behind him should know what hat he is wearing (reason: if the second child is wearing a red hat, then the third child standing behind should know his white hat, and then the second child also knows that he is wearing a red hat; However, the third child did not respond, so the second child knew that he was wearing a white hat.

But the second child didn't respond, and the boss knew he was wearing a white hat.