GMAT 逻辑分析题 (14)

sdcar2010

Recently discovered prehistoric cave paintings on Diaoyu Dao, or Uotsuri Jima in Japanese, have archaeologists puzzled. The traditional theory about these cave paintings was that they were mostly a description of the favorite diets of the prehistoric painters. This “diet” theory cannot be right, because these painters must have needed to eat the animals populating the East China Sea if they were to make a living on the island and to sail across the East China Sea, but there are no paintings that distinctively depict these sea creatures in the cave.

Each of the following statements, if true, weakens the argument against the traditional theory about the cave paintings EXCEPT:

a) While living on the island, the cave painters hunted, caught, and ate land animals.
b) A significant part of the original cave paintings on the islands were lost during a tsunami.
c) The cave paintings that were recently discovered on the islands pictured many land animals.
d) The cave painters learned the Chinese traditional method of how to preserve meats.
e) These cave paintings on the island were completed by the original islanders who ate the meat of farmed land animals.

梦离ouzi

D吧。Since they had learned the chinese traditional method implies that they must have made a living on the island and had sailed across the East China Sea. Hence, statement D supports the argument against the theory.

sdcar2010

This is a tricky question.  You need to read the question prompt to know CLEARLY which theory or argument to support or weaken.

fielcy

Is that right to choose D which is irrelevant?

BTW, it is so surprise to know that you made up those questions by yourself.
awesome~

kevin0214

P( live on the island and sail across Sea)， Q(eat sea creature)，X(paintings depict sea creature)，Y(we see these paintings)
IF P,THEN Q,  IF Q, THEN X, IF X, THEN Y
原文考古学家给出的是Q和X的关系，如果考古学家是正确的，则Q→X。
现在已知非Y，原文ARGUMENT说因此Q推不出X。这个论证很弱，因为这条链那么长，很多地方都可以用来解释非Y的发生。
A表达: P推不出Q，可以解释非Y；
B表达：X推不出Y，可以解释非Y；
D表达：P推不出Q，可以解释非Y；
E表达：非P，可以解释非Y。

答案选C，没有表达任何关于这个推理链的东西。

kevin0214

这题很有意思，要写出来才完全弄清这个链条，特别是考古学家的解释和题目的argument到底在什么地方有抵触我想了挺久。

sdcar2010

Very nice logic chain!  C is the only irrelevant answer choice among the five.  The other all weaken the author's argument.

Good job, Kevin.

梦离ouzi

好难啊。。下次要乖乖拿起笔来分析了。If these questions were to appear on gmat it would take quite long to figure out.  你们好聪明唉。

fielcy

看题目太草率了
看来我逻辑还得有待加强
期待楼主的更多的题目

efrenreyes

楼上的没有一个是正解，不过答案确实是C。各位热烈的讨论，加深了我此前就有的一个判断，即人的逻辑能力主要是先天决定的，并且很难通过学习得到加强。后天的训练，很大程度上只是帮助你在处理你先天逻辑能力本就可以胜任的问题时，可以更加地熟练，表现在做题上就是速度会更快。但是，不会让你拥有你原本并不具备的处理复杂逻辑推理的能力，在应对该类问题时，你的推理依然会是漏洞百出的，尽管你仍然有可能会象这题一样，在多个选项中恰好蒙对答案。

回答的最努力的kevin，你的推理错误百出，我只指出你最开始的一个。考古学家的假设给出的Q和X的关系，并不是你所说的Q(eat sea creature) → X(paintings depict sea creature)，恰恰相反，应该是：X → Q。并且如果你确实是在全部写出来以后，才完成了对此题的推理的话，那么很遗憾你的逻辑能力应该很难再上一步了。

好比这题的X → Q还是Q→X，一般人容易弄混（但这恰恰反映了你最原始的逻辑能力）。可能你认为二者是充要条件（暂且假设考古学家是对的），但是其实二者并不是，因为painters也可以Q(eat sea creature)，但仍然“非”X(paintings depict sea creature)，如果sea creature不是favorite diets of the prehistoric painters的话，则考古学家的假设仍然是对的。

原文试图用"there are no paintings that distinctively depict these sea creatures" ，基于"painters must have needed to eat the animals populating the East China Sea"这个假设，去argue against 考古学家的假设。注意按照题意"there are no paintings that distinctively depict these sea creatures" ，已经是一个客观事实，不容否认。那么要weaken the argument ，可以从以下几个方面入手：

1、weaken "painters must have needed to eat the animals populating the East China Sea" "if they were to make a living on the island "，这只是个假设，是可以weaken的。比如选项A，如果the cave painters hunted, caught, and ate land animals成立，那么假设就直接被weaken了，因为painters caught and ate land animals，因此不是must have needed to eat the animals populating the East China Sea；同理，选项E也直接weaken了该假设；

2、weaken "painters must have needed to eat the animals populating the East China Sea" " if they were to sail across the East China Sea" 。比如选项D，因为painters learned how to preserve meats，因此不是must have needed to eat the animals populating the East China Sea when they were sailing across the East China Sea；

3、指出原题"there are no paintings that distinctively depict these sea creatures"这个客观事实不全面，不具代表性。比如选项B，如果"A significant part of the original cave paintings on the islands were lost"成立，则"there are no paintings that distinctively depict these sea creatures"这个事实不全面，因为可能有大量的paintings that distinctively depict these sea creatures were lost；

4、选项C并不是无关选项，"paintings that were recently discovered on the islands pictured many land animals"具体化了"there are no paintings that distinctively depict these sea creatures"这个原题中已经给出的客观事实，那么如果考古学家的假设是对的，则 X(paintings depict land animals) → Q(painters eat land animals as favorite diets ) ，与原题所提出的"painters must have needed to eat the animals populating the East China Sea"(暗示sea creatures 才应该是 painters' favorite diets）的假设相悖。

综上，选项C是题设所求正确答案。


p.s.写了以上这么多，不是为了打击任何人，又或者炫耀什么。对于个人而言，做逻辑题是准备GMAT考试最有乐趣的一个部分（数学实在太过简单了），因此非常乐意把推理过程拿出来和大家分享。我之所以费力打了这么多字，是希望大家明白一个道理，逻辑能力是很难后天加以提高的，与其把时间和精力投入在边际产出如此小的一个方向上，实在不如多背背单词和语法，毕竟这些东西是死的，可以通过后天机械的训练和记忆大幅予以提高。