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.”

He continued, “Anybody caught breaking this rule the second time will be fined $60. Being caught a third time will incur a hefty fine of $180. Are there any questions?”

At this, a male student in the crowd inquired, “How much for a season pass?”