国际顶尖MBA申请交流平台--TOPWAY MBA

标题: [求助]天山 4-29 [打印本页]

作者: apple1 时间: 2005-1-27 13:46 标题: [求助]天山 4-29

Q29

The toll for crossing a certain bridge is $0.75 each crossing. Drivers who frequently use the bridge may instead purchase a sticker each month for $13 and then pay only $0.3 each crossing during that month. If a particular driver will cross the bridge twice on each of x days next month and will not cross the bridge on any other day, what is the least value of x for which this driver can save money by using the sticker?

A 14

B 15

The answer is B but I think the answer is A

0.75×2 ×N＜13+0.3×2 ×N

作者: sammen 时间: 2005-1-27 22:50

n<14.44,如果n取14的时候0.75X2X14=21;13+0.3X2X14=22.4还是不划算的对不,只有当n=15的时候才可以.

作者: apple1 时间: 2005-1-28 13:11

还是不这么明白。

欢迎光临国际顶尖MBA申请交流平台--TOPWAY MBA (http://forum.topway.org/)