Then if we assume that the grade of Class One in seven years is the last, there is no guarantee that this class will not be eliminated before the play-offs. That is, if the grade of class one in seven years is 1 win 2 losses, the remaining three classes will be allocated 5 wins and 4 losses; According to observation, the remaining three classes must be assigned four defeats, so there must be one class with two defeats, which is the same as the result of seven years 1 class. From this, it can be concluded that if class one in seven years wins at least one game, it will not be eliminated before the knockout stage.
Through the above verification, it can be seen that the seventh grade class one and other classes tied for the last place in a single cycle, so there is a loss in the play-offs, so they may not be able to qualify.
This question is actually very simple to think of with your brain, but it is not easy if it is written logically. I hope it will help the landlord. Anyway, I came in to solve the volleyball problem, but it turned out to be a math problem, depressed ~
If you win at least one game, you will never be eliminated before the play-off.
Because there is no draw in the volleyball match.
So the possible situation is:
A, 1 team win 3, 1 team win 2, 1 team negative 1, 1 team win 2, 1 team negative 3, 3 negative direct elimination.
B, 1 The team won three games, all three teams were 1 winning and 2 losing, and finally the three teams played a play-off.
C, 2 teams win 1 lose, 2 teams win 1 lose, and finally 2 teams play the play-offs.
If you only win 1 game, there is no guarantee that it will appear. It depends on the play-offs.
One * * * six games.
Grade 7 1 class single round robin can win at least 1.
It means that the other three classes win at most five games.
So none of the three classes can do better than 1 class.
This class can ensure that it will not be eliminated before the play-offs.
If you only win one game, you may not be qualified.
Winning two games is sure to qualify.