gwd-6-33

dancingfrog

Q58: (6-33)

Crowding on Mooreville’s subway frequently leads to delays, because it is difficult for passengers to exit from the trains.  Subway ridership is projected to increase by 20 percent over the next 10 years.  The Metroville Transit Authority plans to increase the number of daily train trips by only 5 percent over the same period.  Officials predict that this increase is sufficient to ensure that the incidence of delays due to crowding does not increase.

Which of the following, if true, provides the strongest grounds for the officials’ prediction?

1. By changing maintenance schedules, the Transit Authority can achieve the 5 percent increase in train trips without purchasing any new subway cars.


2. The Transit Authority also plans a 5 percent increase in the number of bus trips on routes that connect to subways.


3. For most commuters who use the subway system, there is no practical alternative public transportation available.


4. Most of the projected increase in ridership is expected to occur in off-peak hours when trains are now sparsely used.


5. The 5 percent increase in the number of train trips can be achieved without an equal increase in Transit Authority operational costs.

   Answer: D

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之前有nn的解释选D的原因是

If D, "Most of the projected increase in ridership is expected to occur in off-peak hours when trains are now sparsely used," is true, then obvious these ridership increase won't cause much more crowding, and the official's prediction would be strengthened.

但是原文中official‘s prediction是Officials predict that this increase is sufficient to ensure that the incidence of delays due to crowding does not increase.

即增加5％的trips可以足够（sufficient）使得拥挤造成的晚点不再增加，我的理解是晚点的增加是来自于未来十年20％more ridership的增加。如果增加班次只是为了使原来的拥挤不恶化，那么其意义何在？所以要support prediction 是不是要从5％的增加能否offset未来十年20%ridership入手？

是否A是个好点的答案？

请nn指点！

mindfree

"如果增加班次只是为了使原来的拥挤不恶化，那么其意义何在" is not the concern here at all. You should never think beyond the reasoning of the argument. For example, if the is your concern, how about building highway instead of subway? How about low gas price so that people will drive more? We are not given any information for us to make judgment on such things.

Here all we know is that crowding is to blame for delay. So 20% ridership, is occurs only during off-peak time, will not cause crowding proportionately (20% to 20%). Therefore 5% increase in trips might well mitigate the problem.

dancingfrog

got it,thanks!

helenefz

这题我还没明白。

题中说迟到是因为挤(crowd)造成，D说增加的ridership是在off-peak（非高峰期），那么peak的时间，ridership就没有变化，那么不还是会挤吗？

请指教。

helenefz

再顶一次，盼指教。

谢谢。

helenefz

yoyonline

以下是引用helenefz在2004-12-26 10:59:00的发言：

这题我还没明白。

题中说迟到是因为挤(crowd)造成，D说增加的ridership是在off-peak（非高峰期），那么peak的时间，ridership就没有变化，那么不还是会挤吗？

请指教。

D 是说“projected to increase by 20 percent over the next 10 years. ” 未来十年20％的人数增加大部分会发生在非高峰期，也就是现在不拥挤的时候。 这样现在高峰的人数增加不会有20％那么多。所以增加5％的班次就足够减轻拥挤了。正如你说的“那么peak的时间，ridership就没有变化”， 同时有多5％的火车，那问题就不会恶化了。

helenefz

原来是这样哦。

谢谢。

zhaoshujuanw

yoyonline said:"未来十年20％的人数增加大部分会发生在非高峰期",但是题目中没有信息提供呀。

请赐教

Maggiewjy

其实只要针对题目中的 Officials predict that this increase is sufficient to ensure that the incidence of delays due to crowding does not increase.由于拥挤造成的迟到没有增加。 D中说增加的班次是发生在非高峰期也就是说高峰期的拥挤并没有增加。 否则应该要增加高峰期的班次。

请指教