The next day, Rouer is furious that Lin Suer is still pretending to be a saint. He tells her that she will get her lesson on the upcoming midterm exam and that she can do whatever she wants with him. He says that if she can get first place, he can slap her in the face as he likes. He goes on to say that if he can beat her, she can take off all of her clothes and run around naked for 100 laps on the playground. Rouer goes home and prepares to take the exam. Fifteen minutes later, he wonders why there is so much trouble with math in school. There are two pipes for refilling the pool and for draining the pool. It takes 20 minutes for the pool to be filled and 40 minutes for it to be drained. The staff discovers that the pipe that drains the pool isn't turned on when he starts filling it. He has to wait for another two minutes before he can fill the pool completely.