1. Misha, Petya, Kolya, and Vasya played "podkidnoy durak" (a card game), a total of 16 games were played. Each of them was left "in the fool" at least once. It is known that Misha was left the most, and Petya and Kolya together were left 9 times. How many times was Vasya left "in the fool"?

ANSWER: 1.
Solution: If Petya or Kolya was left behind no less than 5 times, it means Misha was left behind no less than 6 times, therefore Vasya was left behind once (he could not have been left behind 0 times according to the condition).