问题
问答题
An airline passenger is planning a trip that involves three connecting flights that leave from Airports A, B, and C, respectively. The first flight leaves Airport A every hour，beginning at 8:00 a.m., and arrives at Airport B 
hours later. The second flight leaves Airport B every 20 minutes, beginning at 8:00 a.m., and arrives at Airport C 
hours later. The third flight leaves Airport C every hour, beginning at 8.45 a.m. What is the least total amount of time the passenger must spend between flights if all flights keep to their schedules ？
答案
参考答案：
65分钟。
解析：
要使在航班之间花的时间最少，则这些乘客应尽可能地赶上早一点的航班。设乘客上午8点从机场A出发，则于10点30分到达机场B，此时乘客只能乘10点40从B飞往C的航班，并于11点50后才能到达机场C，此时机场C的11点45分的航班刚开走5分钟，所以不得不等下一班，即55分钟以后的哪一班。综上所述，乘客在航班之间所花的时间应为10+55=65分钟。