两道逻辑题求助。。求各位nn前来解答

Cynthia_1

1. Ronald: According to my analysis of the national economy, housing prices should not increase during the next six months unless interest rates drop significantly.
Mark: I disagree. One year ago, when interest rates last fell significantly, housing prices did not increase at all.
It can be inferred from the conversation above that Mark has interpreted Ronald’s statement to mean that
(A) housing prices will rise only if interest rates fall
(B) if interest rates fall, housing prices must rise
(C) interest rates and housing prices tend to rise and fall together
(D) interest rates are the only significant economic factor affecting housing prices
(E) interest rates are likely to fall significantly in the next six months
这一题答案是b。
r说的是housing prices不会增长除非rates下降。
然后m又说，我不同意，一年前的时候，当rates下降了，prices也没有上涨啊！
我觉得m想说的不应该是这个rates的大小不一定会影响prices么，因为他是直接反驳了r说的这个prices的高低与rates的人关系。
但是答案为什么说rates下降的时候，prices有一定会涨呢？是我这个理解有问题么。。希望牛牛可以来指正我的错误。




2. .Some commentators complain that a “litigation explosion” in the past decade has led to unreasonably high costs for U.S. businesses by encouraging more product liability suits against manufacturers. However, these complaints are based mainly on myth. Statistics show that the number of successful product liability suits has remained almost the same, and the average sum awarded in damages has grown no faster than the inflation rate.
Which of the following, if true, would most weaken the argument above?
(A) The number of unsuccessful suits has skyrocketed, imposing huge new legal expenses on businesses.
(B) Several of the largest awards ever made in product liability cases occurred within the last two years.
(C) The rise of the consumer movement has encouraged citizens to seek legal redress for product flaws.
(D) Lawyers often undertake product liability cases on a contingency basis, so their payment is based on the size of the damages awarded.
(E) Juries often award damages in product liability suits out of emotional sympathy for an injured consumer.
这一道题答案是a。我觉得我理解到的是，这一题按照helr的来分类应该属于果因结构。果：这些人的对于国家将要增加costs的抱怨言论是不对的。因：balabala。。
但是我题好像读的有问题。。。
希望有牛牛可以来讲解一下 万分感谢?

Bensontuo

2.

Spot the question type: Weaken ( Weaken the objection )

Cause - litigation explosion to one effect - encouraging more product liability suits against manufacturers as the other cause to lead to one final effect - unreasonably high cost for US business.

Author countered the argument by citing the portion of the suit cases as the example to support its own objection. However, how could only the portion of the number of successful product liability suits be sufficiently enough to represent the whole litigation law suit case regarding one specific characteristic of not bringing high cost ?

Perfect answer - A

Bensontuo

Spot the question type: Method of the reasoning

Structure of the Reasoning

R: Due to an analysis ---> it must be true that if house prices increase during the next six months, interest rats must be dropping significantly.

M: Your conclusion is wrong ( undermine R).  Interest rate fell last year significantly, house price did not increase.

Apparently, the reason why M believes R's claim is wrong is because M mistakenly reverses the conditional logic of R.

B, perfect answer.

Attano

用Manhattan Foundation+Bible的flaw来挑战一下第二题吧～
只看stimulus，它的conclusion就有很大的漏洞，第一个虽然比例不变，但是数量上升对公司也是很大的法律支出（正确答案），第二个flaw是，如此频繁的诉讼活动，是否会导致民众怀疑该公司的产品，进而影响到sale呢？第三，专家说的是high cost，而conclusion辩驳的是remain/no faster，会不会本来的诉讼成本就已经是unreasonably high，或者manufacturer的profit逐渐减少，已经负担不起诉讼费用了呢？
以上三个角度任何一个切入都可以有效的weaken the argument.
如果用helr，那么针对*因：statistic说没问题呀*来削弱，我们就让statistics失去力量，题目给的statistics是proportion，而GMAT中对于proportion最常见的一种削弱就是number。

Ivy蓝蓝蓝蓝

Cynthia_1 发表于 2018-11-29 07:37
原来如此！谢谢你的耐心解答

没事儿～

Cynthia_1

Ivy蓝蓝蓝蓝 发表于 2018-11-28 21:53
充分条件可以推出必要条件，必要推不出充分等等规则和我们中学学的是一样的。但是GMAT里的充分条件和必要 ...

原来如此！谢谢你的耐心解答

Ivy蓝蓝蓝蓝

Cynthia_1 发表于 2018-11-28 21:12
哦哦哦哦哦这道题问的是m所理解的r的意思啊，原来如此。。我一直感觉这个题出的自相矛盾。。我理解有问题 ...

充分条件可以推出必要条件，必要推不出充分等等规则和我们中学学的是一样的。但是GMAT里的充分条件和必要条件怎么判断是规定好的，if/when后面接充分条件，until后面接的是必要条件（你问的应该是R说的话怎么判断充分条件和必要条件吧...）《Bible》第四章里有

Cynthia_1

Ivy蓝蓝蓝蓝 发表于 2018-11-28 20:48
充分条件和必要条件的判断主要是通过idicator, until后面是必要条件，when后面是充分条件，这个知识点bib ...

哦哦哦哦哦这道题问的是m所理解的r的意思啊，原来如此。。我一直感觉这个题出的自相矛盾。。我理解有问题了。。多谢你的解答啦！
这个充分必要是不是和我们中文学得不一样啊，我们中文学的充分必要不是说的是如果可以从a推出来b，但是b推不出来a的话，则a是b的充分不必要条件；回到这一题，不是说的是利率下降导致了房价上涨的么，那为什么利率下降不是充分条件呢。。

Ivy蓝蓝蓝蓝

Cynthia_1 发表于 2018-11-28 20:35
貌似是逻辑大全？还是狒狒？我也忘记了 不好意思啊?
我有两个疑问，一是r说的意思不是利率下降会导致房 ...

充分条件和必要条件的判断主要是通过idicator, until后面是必要条件，when后面是充分条件，这个知识点bible上应该有。M说的是反对的原因（给反例），他理解的R说的话是B选项，我也不知道自己说清楚没,...这题真的蛮绕的
PS: 我觉得如果真题没做完 还是优先做真题比较好~毕竟真题最贴近实战嘛

Cynthia_1

Ivy蓝蓝蓝蓝 发表于 2018-11-28 20:22
第一题在考充分性关系和必要性关系
R: 房价上升--充分条件， 利率下降--必要条件
M: 利率下降--充分条件， ...

貌似是逻辑大全？还是狒狒？我也忘记了 不好意思啊?
我有两个疑问，一是r说的意思不是利率下降会导致房价上涨么？那不就是应该利率下降是充分条件的么。。求解答
二是这个m不是明明就是反对r的说法么，那为什么题目问的是他对前者的转述呢？这个转述就感觉是两者是同向的啊。。我还是不太明白。。