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标题: [求教]OG12 78超速吃罚单-大家总是解释为何选B，没有具体说明为何不选A [打印本页]

作者: nightingale 时间: 2011-3-5 13:16
标题: [求教]OG12 78超速吃罚单-大家总是解释为何选B，没有具体说明为何不选A
Q78.

A recent report determined that although only 3 percent of drivers on Maryland highways equipment their vehicles with radar detectors, 33 percent of all vehicles ticketed for exceeding the speed limit were equipped with them. Clearly, drivers who equip their vehicles with radar detecters are more likely to exceed the speed limit regularly than are drivers who do not.

the conclusion drawn above depends on which of the assumotions?

A Drivers who equip their vehicles with radar detectors are less likely to be ticketed for exceeding the speed limit than are drivers who do not.
B Drivers who are ticketed for exceeding the speed limit are likely to exceed the speed limit reguarly than are drivers who are not ticketed.
C The number of vehicles that were ticketed for exceeding the speed limit was greater than the number of vehicles that were equipped with radar detectors.
D Many of the vehicels that were ticketed for exceeding the speed limit wre located more than once in the time period covered by the report.
E Drivers on Maryland highways exceeded the speed limit more often than diDd drivers on other state highways not covered in the report

首先我支持B选项可以说明问题，是符合题意的。但是请问A选项错在哪里呢？

如果说装了雷达的车更不容易因为超速而吃罚单，那结合题中条件，装了雷达的车吃了更多罚单，不是更应该证明装了雷达的车超速的次数比不装的车多得多么？
OG的解释是这个选项针对吃罚单的问题可能是真的，但与题中关于经常超速的问题不相关。我怎么觉得这个解释有点牵强呢？因为选项明明说的是are less likely to be ticketed for exceeding the speed limit，不是已经和超速联系起来了么？难道就是因为没有明确说在“相同次数”的超速情况下不容易吃罚单么？我怎么觉得这个思维还是不对呢？

希望大家理解了这个选项错误原因的给予解释。
谢谢！

作者: azhuo 时间: 2011-3-5 14:26
A说的是罚单（be ticketed，因为超速）

作者: nightingale 时间: 2011-3-5 14:33
因为超速吃罚单机率小+实际吃罚单多，不是更加可以推出实际超速多么？

我知道B是正着推的，很顺。
可是A可以逆着推啊，感觉也不无道理。

作者: nightingale 时间: 2011-3-5 20:03
有人帮忙解释一下不？

作者: sdcar2010 时间: 2011-3-5 21:34
When you negate A, as you did correctly, you get "Drivers who equip their vehicles with radar detectors are more likely to be ticketed for exceeding the speed limit than are drivers who do not." And this statement is consistent with one of the premise of the argument, therefore the argument still holds IF you follow the logic chain of the author because that's what the author claims! Whether or not the author's conclusion is right or wrong is not our concern for the assumption-type question. We have to treat the author's statements as correct. Since when you negate A, you do not weaken or refute the author's argument, the argument still holds.

作者: nightingale 时间: 2011-3-5 22:47
LS, thank you very much for your explanation, but I am afraid I cannot agree that we need to follow the logic chain of the author just because that's what the author claims.

The CR question asked "the conclusion drawn above depends on which of the assumptions", which means the assumption we selected cannot be ignored when getting the conclusion. Without this assumption, there will be a gap between the premise and the conclusion of the argument. In other words, if only based on the words provided in the argument, there is no "LOGIC" train.

Correct me if I am wrong.

Anyway, you provided a new point which I have not considered before. Thanks very much, sdcar2010.

作者: sdcar2010 时间: 2011-3-5 23:13
In GMAT and LSAT CR questions, the stimulus normally gives a premise and a conclusion. It is paramount to remember, unless the question ask you to identify a faulty argument, the given premise and conclusion are treated as "right" in the sense that if the conditions in the premise is fulfilled, the conclusion is "logically" obtained.

That is the logic chain I am talking about. We only focus on the logic, not the "truth"of the whole argument.

When solving the CR question, it is essential to keep away from adding your own judgement or evaluation of the statements. Focus on the reasoning part.

Therefore, when negating A, the argument still holds because negating A won't affect the "logic" used in the stimulus since it only repeats the premise.

作者: sdcar2010 时间: 2011-3-5 23:16
Assumption means "untold" premise. Thus, when the speaker makes the argument in the stimulus, he assumes the "untold" premise is correct. In that sense, his argument has correct logic chain although he does not specifically STATE the untold premise.

As a test taker, you are supposed to find out which one of the answer choices is the untold premise that the author takes for granted.

作者: nightingale 时间: 2011-3-6 00:33
Still a little confused, but I noticed one difference between A and B.

If we negate A, the argument might hold or not.
If we negate B, the argument definately cannot hold.

It is the difference between the sufficiency and necessity.
So can we say that the assumption this question required is a necessary condition, rather than a sufficient evidence, to reach the conclusion?

作者: sdcar2010 时间: 2011-3-6 01:59
Show me your reasoning why after negating A, the argument might not hold.

Remember, no outside assumptions or opinions. Just follow the logic presented in the stimulus.

作者: nightingale 时间: 2011-3-6 09:10
I finally found an instruction from lawyer:
"一。ASSUMPTION类。假设类分充分型和必要型。充分型是问题问你下列哪个假设，能使原文的结论PROPOERLY推出。必要型是问题问你原文的推理依赖下列哪个假设。他们的作题思路不同。充分类因为原文结论是必须能从证据推出（加上假设），所以方法较简单，将选项加到原文的推理中，如果结论必成立（MUST BE），则为答案，如果结论有不成立的可能性，则错，其中的特例是原文证据和结论的概念差异（GAP），说出这个GAP就是假设。必要类复杂点，总体的方法是将选项取非，如果原文的结论必不成立，则为答案，如果还有成立的可能性，则错。取非就是假设选项是错的。其中有几种特例。一是其他类（其他原因，可能性。。。），它的假设是不存在其他（原因，可能）。另一种是原文证据和结论的概念差异（GAP），说出这个差异就是假设。还有一种是只考虑单方面，其假设是其他方面没影响。其特例是比较两个东东，只比较某方面，便得出一个总体结论，其假设是其他方面没影响。充分类的加进法和必要类的取非法都可用于TEST所有选项，但因时间较长，所以通常方法是用有关无关排除后剩下难分的选项才用这方法，很多情况下通过有关无关排除便只剩下一个。他们的特例则可以直接找答案。"

As I said, I think CR 78 belongs to 必要型.

The next question is, how to differentiate 充分型 and 必要型?

作者: nightingale 时间: 2011-3-6 09:18

Show me your reasoning why after negating A, the argument might not hold.

Remember, no outside assumptions or opinions. Just follow the logic presented in the stimulus.

-- by 会员 sdcar2010 (2011/3/6 1:59:04)

Say, we have 100 drivers, 3 of them equipped their vehicles with radar detectors (we call them RD), and 97 did not (we call them NRD). Each driver drives exceeding the speed limite 11 times during the report period. As we negating A, RD are more likely to be tiketed than NRD, so it is possible that the 11 times for the 3 RD are all tiketed, while the 11 times for the 97 NRD are only ticketed for 67 times in total. Then the report showed that 33% tiketed vehicles are all equipped with radar detector. Under this condition, we cannot get the conclusion that RD are more likely to exceed the speed limit regularly than NRD, since the times they do during a certain period are the same.

This is an extreme example, though. But we can see from this that the conclusion "might" not hold.
This is also why I said, without the assumption the question is asking, the argument itself is not logical.

作者: sdcar2010 时间: 2011-3-6 12:01
<div class="maxcode-quote">

<div class="maxcode-quote">
Show me your reasoning why after negating A, the argument might not hold.<br /><br />Remember, no outside assumptions or opinions.  Just follow the logic presented in the stimulus.<div style="text-align:right;">-- by 会员 <u>sdcar2010</u> (2011/3/6 1:59:04)</div><br /><br /><br /><br /><br />
</div>
<br /><br />Say, we have 100 drivers, 3 of them equipped their vehicles with radar detectors (we call them RD), and 97 did not (we call them NRD).  Each driver drives exceeding the speed limite 11 times during the report period.  As we negating A, RD are more likely to be tiketed than NRD, so it is possible that the 11 times for the 3 RD are all tiketed, while the 11 times for the 97 NRD are only ticketed for 67 times in total.  Then the report showed that 33% tiketed vehicles are all equipped with radar detector.  Under this condition, we cannot get the conclusion that RD are more likely to exceed the speed limit regularly than NRD, since the times they do during a certain period are the same.<br /><br />This is an extreme example, though.  But we can see from this that the conclusion "might" not hold.<br />This is also why I said, without the assumption the question is asking, the argument itself is not logical.<div style="text-align:right;">-- by 会员 <u>nightingale</u> (2011/3/6 9:18:20)</div><br />
</div>
<br /><br />

Interesting example.  However, it is not what the stimulus describes. First, the stimulus talks about vehicles, not drivers. Second when it says 33% of the ticketed vechiles are equipped with RD, it means 100 different vehicles, not the same car being ticketed over and over.

作者: nightingale 时间: 2011-3-6 15:39
Oh, LS, use greaterer numbers, 300 RD and 9700 NRD with one exceed each. Still, 33 of RD and 67 of NRD are ticketed. Then we can solve the "over and over" problem.

The theme here is that the conclusion might not hold.

作者: sdcar2010 时间: 2011-3-6 21:31

Oh, LS, use greaterer numbers, 300 RD and 9700 NRD with one exceed each. Still, 33 of RD and 67 of NRD are ticketed. Then we can solve the "over and over" problem.

The theme here is that the conclusion might not hold.

-- by 会员 nightingale (2011/3/6 15:39:42)

First, your example is wrong, again, because you used the following premise/assumption: Both RD and NRD has the same rate of exceeding speed limit. The stimulus never says that.

Second, if you start with this "equal rate" premise/assumption, of course you will reach a different conclusion from that of the stimulus because you already set the conclusion you want to reach in your premise/assumption. This is akin to circular reasoning.

作者: nightingale 时间: 2011-3-6 22:40
It is not my premise/assumption. It is just an example of possible condition to show that when the premises of the questions are met (3% and 33%), the conclusion (more regularly) might not hold.

As I said, I already know the difference between A and B, based on lawyer's theory.
It is just another question I need to figure out: when the question is 充分型, and when it is 必要型.
If you would like, we can move on.

作者: sdcar2010 时间: 2011-3-6 22:57
"300 RD and 9700 NRD with one exceed each" That is an additional premise on top of the 3% and 33% premises provided by the author. Therefore, it is an outside info which is not allowed in CR question.

As to "when the question is 充分型, and when it is 必要型.", the former is justifying assumption while the latter is necessargy assumption.

Necessary: depend on, rely on, need, require, must-be-true.

作者: sdcar2010 时间: 2011-3-6 23:16
For a necessary assumption question, the correct answer is the one that is necessary for the conclusion to be drawn or to depend on: the conclusion of the stimulus cannot be drawn without it; but at the same time, the necessary assumption alone is not enough to bring about the conclusion of the stimulus.

As to justifying assumption questions, the correct answer is the one that is sufficient for the conclusion to be drawn: the answer choice itself is enough to lead to the conclusion; but the correct answer choice does not necessarily have to be the ONLY case which makes the conclusion righ. That is, there could be other routes for justifying the same conclusion.

作者: nightingale 时间: 2011-3-9 01:18

As to "when the question is 充分型, and when it is 必要型.", the former is justifying assumption while the latter is necessargy assumption.

Necessary: depend on, rely on, need, require, must-be-true.

-- by 会员 sdcar2010 (2011/3/6 22:57:24)

Thanks very much, sdcar.
Do we have any key words for the justifying assumption? or just without the ones for necessary assumption, the question type should be justifying assumption?

作者: zsy020584 时间: 2011-3-9 05:45
A的话是错的，和结论相反，结论是装雷达更加可能吃罚单，A值得是更不容易吃罚单。
这道题主要点在regularly, 因为他推论用的证据是 33%的有雷达的被罚，退出装雷达的车更容易“regularly经常的”吃罚单。
所以明显的推论过程有gap,补充gap就是完整。也就是assumption

作者: chuckbass 时间: 2011-3-9 23:51
我觉得问题出在regularly这个词上，这个题的结论是more likely to exceed the speed limit regularly than are drivers who do not. 但之前所说的with radar or not之类的并没有提到超速这个事是regularly的，如果没有B 这个assumption前面所介绍的一些数据和结论挂不上勾。答案A并不能说明为什么结论提到的regularly这个问题

作者: nightingale 时间: 2011-3-14 11:50
我觉得没有反啊，结论是装雷达的更加可能超速，A选项是说装雷达的不容易吃罚单，二者不矛盾。
其实我也知道补充gap就是assumption，也知道B是很符合题意的，只是比较钻牛角尖地觉得A选项其实也可以推出来结论。呵呵。

不过regularly这个问题有一定道理。
多谢上两楼zsy020584和chuckbass 的提醒！

作者: pandaforever 时间: 2011-3-31 16:32
“只有0.03的车装了雷达，但是在因超速被开罚单的车中，装了雷达的占0.33，惯性思维下，我们就认为装了雷达的车主比没装雷达的车主更爱超速。 ”
这里有一个GAP就是如果没被罚的车中也有爱超速的怎么办？？？只有将爱超速的车限制在被罚的车中（即没被罚的都不爱超速），才能说装了雷达的比没装的爱超速。因为这样才能确定大部分装了雷达的车爱超速，而没装雷达的车中只有一小部分爱超速。

作者: ddworld99 时间: 2011-5-28 03:21
题目隐藏的意思是这样：因为经常超速的人更经常被开罚单，所以他们由于怕再被开罚单才会装雷达，因此很高比例装雷达的人都被开了罚单。
解题过程是上面那个过程的逆推：被开过罚单的人很高比例都装了雷达---》装了雷达的人都是经常超速的人---》被开过罚单的人更经常超速

作者: hhhlll 时间: 2011-5-30 19:26
我觉得没有反啊，结论是装雷达的更加可能超速，A选项是说装雷达的不容易吃罚单，二者不矛盾。
其实我也知道补充gap就是assumption，也知道B是很符合题意的，只是比较钻牛角尖地觉得A选项其实也可以推出来结论。呵呵。

不过regularly这个问题有一定道理。
多谢上两楼zsy020584和chuckbass 的提醒！

同样疑惑A为啥不对！期待大牛解释

作者: sdcar2010 时间: 2011-5-30 20:52
A选项其实也可以推出来结论 does not make A necessary for the argument to hold. Only if when negating A makes the argument fall apart, A is necessary for the argument.

作者: lemonles 时间: 2011-6-8 22:02

因为超速吃罚单机率小+实际吃罚单多，不是更加可以推出实际超速多么？

我知道B是正着推的，很顺。
可是A可以逆着推啊，感觉也不无道理。

-- by 会员 nightingale (2011/3/5 14:33:16)

正解啊正解，茅塞顿开

作者: connie飘着 时间: 2011-6-9 07:45
I think it is because of the main point different from the main sentence.
A BE TICKED
B exceed the limit speed

if u need conculd that people who exceed speed limit more, must comes from their behavior, not the result of his behavior.

作者: 小福娃欢欢 时间: 2011-7-21 20:43

A选项其实也可以推出来结论 does not make A necessary for the argument to hold. Only if when negating A makes the argument fall apart, A is necessary for the argument.

-- by 会员 sdcar2010 (2011/5/30 20:52:32)

头一次看到这位大侠也写了几个中文字，很是亲切

作者: superbat28 时间: 2011-8-3 16:28
我去。。顶一个。。看他俩辩论的真有收获……

作者: anye199117 时间: 2011-10-5 16:46
求中文……

作者: jj0615 时间: 2011-10-14 19:58
顶一个

作者: lan0604 时间: 2012-3-14 13:49
顶！大牛辩论给力！

作者: jeffjarrett 时间: 2012-11-24 05:10
如果没看错的话，A和B一个在比较两种被罚的可能性，一个在比较两种超速的可能性，原文的结论就是在比较两种不同装备的司机超速的可能性，不管推不推如何推，打死我都选B。

作者: 高富帅的情敌 时间: 2012-12-11 15:59
居然没有人说选D 其实D才是真相

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