## 65. Second Round

Both brothers entered the house. Soon, one of them came out with a card in his pocket and declared:

- If I am Tralala, then the card in my pocket is not of a black suit.

Who was it?

This problem seemed much more difficult to Alice than the first one, but in the end, she solved the second problem too.

So, who was it?
65. Second Round (Red and Black). The speaker, in essence, claims that he is not Tralala with a red card in his pocket. The statement he made must be true, because if he were Tralala with a red card in his pocket, then (since he has a red card) he could not lie and claim that he is not Tralala with a red card in his pocket. Therefore, it is true that he is not Tralala with a red card. Since his statement is true, he must actually have a red card in his pocket. And since his statement (that he is not Tralala with a red card) is true, he must be Trulala with a red card.