ChaseDream

标题: GWD-8-Q21,请NN指点 [打印本页]

作者: 云的足迹    时间: 2007-10-3 13:20
标题: GWD-8-Q21,请NN指点

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash.  In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

 

Which of the following is required for the revamped collection program to achieve its aim?

 

A.       This year, no materials that city services could separate for recycling will be incinerated.

B.        Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residue ash.

C.        Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.

D.       The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

E.        The total quantity of refuse collected by Shelbyville city services this year will be no greater than that collected last year.


 答案是D,我选A了,题目里不是说目标是减少到一半么,D里假设没个TRUCK的转载都比原来少,那不一定是少到一半了啊,不太明白,请NN指点一下


作者: 云的足迹    时间: 2007-10-3 13:22

上面的太小了,再发一下,黑黑

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash.  In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

 

 

Which of the following is required for the revamped collection program to achieve its aim?

 

 

A.       This year, no materials that city services could separate for recycling will be incinerated.

B.        Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residue ash.

C.        Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.

D.       The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

E.        The total quantity of refuse collected by Shelbyville city services this year will be no greater than that collected last year.


 答案是D,我选A了,题目里不是说目标是减少到一半么,D里假设没个TRUCK的转载都比原来少,那不一定是少到一半了啊,不太明白,请NN指点一下


作者: kevinli120    时间: 2009-8-8 13:08

文章结尾说通过recycle减少要焚烧垃圾的truckloads到去年的一半,以减少产生的ash到去年的一半。

产生的ash的量 = number of 要焚烧垃圾的truckloads * 每truckloads产生的ash量

number of 要焚烧垃圾的truckloads 已经减少到去年的一半了,要想产生的ash的总量为去年的一半,必须要求就是per truckloads 产生的ash量不会比去年多。否则,每truckloads要焚烧的垃圾产生的垃圾量为去年的100倍,减少一半truckloads也无济于事


作者: wxsimon    时间: 2009-9-18 09:39

D确实更具说服力,那A错在哪儿呢?

减少truckload的方法是recycle,烧truckload里装的refuse占一半,需要recycle的refuse占一半,那如果recycle的那一半也有一部分拿来烧(A取非),那么这个total ash的量会怎么样呢?是不是A不能确定到底是会增多还是会减少才不选的?


作者: 没办法1987    时间: 2009-9-18 10:20

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash. 
                
In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

Which of the following is required for the revamped collection program to achieve its aim?假设

此题为:方法——>目的 型。判断的标准是“该方法是否能达到目的”  目的仅为“reduce the amount of residue ash

A.      This year, no materials that city services could separate for recycling will be incinerated.

A主要错在“不必要”,no materials 太强烈了,取非:some materials will be incinerated 还是会达到目的:会减少灰尘

D.      The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

取非,削弱


作者: wxsimon    时间: 2009-9-19 15:00
以下是引用没办法1987在2009/9/18 10:20:00的发言:

Last year all refuse collected by Shelbyville city services was incinerated.  This incineration generated a large quantity of residue ash. 
    
In order to reduce the amount of residue ash Shelbyville generates this year to half of last year’s total, the city has revamped its collection program.  This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year’s number. 

Which of the following is required for the revamped collection program to achieve its aim?假设

此题为:方法——>目的 型。判断的标准是“该方法是否能达到目的”  目的仅为“reduce the amount of residue ash

A.      This year, no materials that city services could separate for recycling will be incinerated.

A主要错在“不必要”,no materials 太强烈了,取非:some materials will be incinerated 还是会达到目的:会减少灰尘

D.      The refuse incinerated this year will generate no more residue ash per truckload incinerated than did the refuse incinerated last year.

取非,削弱

取非,削弱

弱问,a取非,some materials that city services could separate for recycling will be incinerated。 incineration会产生ash,那么本来是recycle不产生ash的现在拿来烧就产生了ash,达不到减少至一半的目的啊,总的ash会比现在的一半多一点。。


作者: cyr93    时间: 2010-7-26 18:29
为什么不能选C呢
作者: InfiniteAlex    时间: 2014-9-29 21:47
很赞,谢谢
作者: Olivia2Chicargo    时间: 2016-8-11 19:36
stem:  

Last year,
all refuse(N truckload)--->incinerated--->ash

This year,

All refuse --- separate for recycling ---> refuse to be incinerated (resulting in half the previous year's truckloads N/2) ---- incinerate this left over refuse ----> ash (which is half the last year's quantity)

Therefore, this year only half the amount of ash is being incinerated. So, ttl refuse for incineration= truckloads numbers* the ash per truck load.  So, unless each truckload generates less residue ash than it did last year, the objective cannot be achieved.


排除 AC 的关键是 half of last year.  AC 都可以起到作用, 但是由于缺乏具体数据支持, 无法证明可以减少一半。


这是道 assumption 的问题, 也就是必要条件, 如楼上所说也是个 方法到目的的问题, 这个题的点就是补上从half number of truckloads 到 half amount of ash 的 gap, 那就是 每车的ash amount 不比去年多。

作者: huihlin    时间: 2016-10-17 12:48
kevinli120 发表于 2009-8-8 13:08
文章结尾说通过recycle减少要焚烧垃圾的truckloads到去年的一半,以减少产生的ash到去年的一半。产生的ash ...

同意!               
作者: meiyw    时间: 2016-12-19 19:35
Olivia2Chicargo 发表于 2016-8-11 19:36
stem:  

Last year,

解释的忒别好。请问A为什么不能作为一个必要选项,因为如果循环的refuse也烧了,这个方法也等于屁用没有,那么A能不能当成是必要条件呢?
作者: 清酉湘竹2018    时间: 2018-11-3 12:21
我本来也错选了A。分析后可得A补充的是前提信息,与逻辑链无关。
措施/前提:通过回收部分垃圾使得要焚烧的truckload减半
结果/结论:残灰排量减半

A讲的是前提中的信息,并没有完善逻辑链中的“链”
GMAT CLUB的解释很好:
Let's say (A) doesn't happen, and some material that COULD have been separated for recycling gets incinerated instead. This would be unfortunate, but it would not change the GIVEN information. We already know that city services WILL reduce the number of truckloads to half of last year's level. That reduction in truckloads will occur even if city services sends some recyclable material to the incinerator. Thus, (A) is not required and can be eliminated.

作者: liangyay    时间: 2020-5-22 20:01
今天刚做了这个题,我也选错了A 后来发现是错在没有理解选项的语义。
原文是说 city service 'will separate for recycling enough refuse (materials) to reduce' 而选项A说的是’materials could separate for recycling'。
后者其实指的是更大的范围. 举个例子就是这些refuse里面有70%是 could separate for recycling的,但是目标是减低refuse到50%即可,那么 20% could separate for recycling的也会可能会被燃烧。所以燃烧的是不是 material could separate for recycling并不会影响达到减少ash到50%的目标

作者: 萬雷天牢引    时间: 2022-3-14 15:27
wxsimon 发表于 2009-9-18 09:39
D确实更具说服力,那A错在哪儿呢?减少truckload的方法是recycle,烧truckload里装的refuse占一半,需要rec ...

看一下!               




欢迎光临 ChaseDream (https://forum.chasedream.com/) Powered by Discuz! X3.3