## 66. Third Round

In this round, one of the brothers, coming out of the house, said:

- Either I am Tra-la-la, or I have a card of black suit in my pocket.

Who was it?
66. The Third Round (Red and Black). "Either-or" means "at least one of the two" (and possibly both). Therefore, if the brother who came out of the cottage had a card of a black suit, it would be true that either he is Tralala or he has a card of a black suit. But this would mean that the holder of the black card made a true statement. Since this is impossible, the one who spoke cannot have a card of a black suit. Therefore, he must have a card of a red suit, and his statement must be true. In turn, this means that either he is Tralala or he has a card of a black suit. Since the second alternative has been proven false, our hero is Tralala with a red card in his pocket.