On the first day of college, the dean addressed the students, pointing out some of the rules:

　　“The female dormitory will be out-of-bounds for all male students, and the male dormitory to the female students. Anybody caught breaking this rule will be fined $20 the first time. Anybody caught breaking this rule the second time will be fined $60. Being caught a third time will cost you $180. Are there any questions?”

　　One student raised his hand and asked, “How much for a season pass?”