6.3. Oleg, Igor, and Anya are in the 6th grade. Among them, there is the best mathematician, the best chess player, and the best artist. It is known that:
a) the best artist did not paint their own portrait, but painted Igor's portrait

b) Anya has never lost to boys in chess.

Who in the class is the best mathematician, the best chess player, and the best artist?
Solution: Since Anya did not lose to the boys in chess, she is the best chess player. Since the artist did not paint his own portrait but painted Igor's portrait, Igor is the best mathematician, and Oleg is the best artist.

Answer: Oleg is the best artist, Anya is the best chess player, Igor is the best mathematician.