GMAT邏輯思維體系?

01-23

GMAT的邏輯思維體系是怎樣的？怎樣貫徹到他的邏輯題中的？他的邏輯體系是形式邏輯嗎？要怎麼解決gmat的邏輯題？

這種問題還是上CD上問會比較靠譜。如果要充分回答題主的問題都能出小本書拿去賣錢了。

簡單說幾句，GMAT邏輯其實非常簡單，絕對沒有說為了trick考生而故意設陷阱，GMAC所講的邏輯絕對是最生活、最簡單、最直白的邏輯（simple and plain)。但是第一次接觸GMAT邏輯可能會有不適應，做一遍OG和OG分冊，感受一下自己邏輯和GMAT邏輯的差異，自己動動腦子什麼都明白了。

可以說邏輯是GMAT最簡單的部分，只要練出了所謂「題感」，干擾選項、無關選項、與題設直接矛盾選項等等一眼即明，邏輯不丟分不是問題，給RC、SC騰出充足時間。當然前提是閱讀能力要強，題目能一遍看懂。

雖然推薦CD，但是不推薦bible等任何輔導資料，也不推薦任何一位大牛的邏輯方法，我個人還是覺得邏輯靠自己弄明白是便捷的方法。方法非常簡單，不懂的Google原題，看大牛們的討論。每道題都弄懂為止，但是切記不要鑽牛角尖。

GMAT邏輯題總結之 -- 小J同學沒有男朋友

以下為本人6年前考GMAT時總結出來的趣味思路，希望有助於大家理解常見邏輯問題和選項套路。

題干：

在19-20歲之間，J同學體重3位數，J同學沒有男朋友

[結論題]

正確選項：

a同學是J同學的男性朋友，但J同學真的不是有男友(paraphrase)

錯誤選項：

J同學真是悲慘（沒有給出的信息）

J同學絕對不可能有男朋友(絕對化)

J同學要是學習金融專業，就會有男朋友（無端涉及金融和錢一類）

——————————————————

[Weaken削弱題]

正確選項：

J同學體重在2位數和3位數間搖擺，J同學沒有男友（削弱條件）

J 同學體重3位數，曾經有過男朋友（削弱結果）

J同學覺得戀愛不靠譜，J同學沒有男朋友（給出他因）

X同學體重2位數，X同學沒有男朋友(無因有果)

Y同學體重也3位數，Y同學有男朋友（有因無果）

其實因為J同學沒有男朋友，所以體重保持3位數（因果倒置）

被證明，體重3位數和有沒有男朋友之間沒有相關關係（無關係）

錯誤：

J同學體重3位數，J同學其實是有男朋友的（削弱不是證否）

調查表明大多數人的密集戀愛期是20-25歲（削弱前提）

J同學不是lesbian，她沒有女朋友（無關）

——————————————————————

【Support加強】

正確選項：

3位數體重使身材缺乏優勢，在外表上競爭力下降，J同學沒有男朋友（加強推理過程）

目擊者證明，J同學和其男性朋友沒有親密舉動（加強結論）

可能的原因是，現代男生喜歡3位數體重女生，但據調查發現，財大男生並非如此（彌補漏洞）

種種證明，J同學沒有男朋友原因是且僅是其體重（排除他因）

Z同學體重3位數，也沒有男朋友（有因有果）

α同學體重2位數，有男朋友（無因無果）

錯誤選項：

19-20歲時間從19歲第一天到20歲最後一天精確計算（加強前提）

————————————————————————

【假定題】

正確選項：

身高170不會導致J同學沒有男朋友（滅他，defender）

體重是男性擇偶的首要標準(搭橋，supporter)

——————————————————————————

【評估題】

正確選項：

體重3位數以上真的是無男友的最主要原因嗎？（關鍵問題）

錯誤選項：

19-20歲不戀愛正常嗎？（無關）

找出了當年自己寫的這點東西，真羨慕青春的你們，祝看到這篇的你取得滿意的GMAT成績！加油！

撰稿人：趴趴GMAT老師 Susan

【獨家原創】GMAT邏輯解題思路（一）——Assumption/weaken/strengthen

GMAT邏輯一直是中國學生最頭疼的題型，當年在準備GMAT的過程中，我也曾被邏輯弄得摸不著頭腦。但是，今天在這裡想跟大家說GMAT邏輯並不難，之所以頭疼只是因為你以前從來沒有見過這種題型。一旦掌握了解題方法，GMAT邏輯一定是GMAT VERBAL部分最容易拿分，也最好複習的部分。GMAT邏輯不像語法需要記憶大量的語法點或者以一個外國人的身份判斷怎麼樣的表達最地道，也不像閱讀需要快速準確的閱讀理解能力。邏輯歸根到底就是一種分析問題的能力。

邏輯按照類型可以分為assumption/weaken/strengthen/
conclusion/boldface等幾種類型。很多培訓機構針對不同的題型有不同的解題方法，這樣的好處是可以迅速地了解各種題型。但是在實戰中，如果考生先判斷題型，再按照相應的方法解題往往會用掉很多的時間，更別提一開始就判斷錯題型的情況。所以我個人的建議是解題方法上不要刻意區分不同的題型，任何邏輯題最終要達到的效果是一樣的，那就是things make sense, 即問題能說清了。

在正式開始講之前，先做兩個定義：

Facts：題干中給出的信息（它們一定是正確的）

Conclusion：題干中由Facts推出的結論

正式講解開始

根據邏輯順序不同，可以將其邏輯分為三大類，以堆積木為例子（沒錯，說的就是小孩子常玩的堆積木）：

1. Assumption/weaken/strengthen

積木已經堆好了（題干中已經有conclusion）

Assumption: 這個積木之所以能拼好是因為除了使用已經提供的原料A（題干中的facts），我還使用了其他沒有擺出來的原料B（assumption）。如果沒有這個原材料B，這個積木就會塌。

Weaken：在這個拼好的積木的基礎上，加上一個新的東西（weaken條件），這個積木變得沒有以前那麼穩，更容易塌。

Strengthen:在這個拼好的積木的基礎上，加上一個新的東西（Strengthen條件），這個積木變得更穩，更站的住腳。

總結起來：

Assumption 條件： Facts –Assumption 條件 è conclusion 不成立

Weaken條件：Facts + Weaken條件 è conclusion 成立的概率降低

Strengthen 條件：Facts + Strengthen 條件 è conclusion 成立的概率變高

2. Conclusion

你的面前有一堆原材料（facts），你可以拼出一個什麼東西（conclusion）。

3.
Boldface

你面前有一個拼好的積木，其中某一塊積木在這個作品中是起什麼作用的？（例如：地基，屋頂，支撐的柱子等）

今天的重點是Assumption/weaken/strengthen題型，我們先舉一個中文的例子：

題干：小明剛畢業來上海工作，他需要租房子。目前他手上有兩套候選的房子，一個1000/月，一個3000/月，因此他應該選3000/月，因為這個房子住起來更舒服。

在看問題之前我們先把facts conclusion整理出來，

Facts: 小明要租房，一個1000/月，一個3000/月

Conclusion: 應該租3000/月，因為更舒服

從facts到conclusion，邏輯的漏洞在於作者做了假設，第一：房子越貴越舒服（題干中沒有提到）；第二：小明找房子只關注房子是否舒服。

因此如果問題是，

1. underlying assumption是什麼？

答案即為：房子越貴越舒服（題干中沒有提到）；小明找房子只關注房子是否舒服。任意一個即可。

2. 什麼可以weaken這個論點？

答案可以為：房子的價格跟房子是否舒適沒有直接的關係；小明覺得價格也是一個需要考慮的因素（住得舒服是一方面，但也要省錢）；小明希望住得地方可以離公司近一些，而3000的比較遠，等等。

3. 什麼可以strengthen這個論點？

答案可以為：研究標明，房子越貴越舒服；小明很看重或者只看重房子的舒適程度；小明對房子額價格不敏感，等等。

通過上面這個例子總結一下GMAT邏輯題的解題方法：

1. 讀題干，找出Facts Conclusion

2. 分析從Facts推導到Conclusion的過程中的邏輯漏洞

3. 看問題，根據第二步發現的問題，找出相應的解答

（1）如果是assumption題，答案需要是邏輯漏洞的反面（取非）

（2）如果是weaken題，答案即為某一個邏輯漏洞

（3）如果是strengthen
題，答案可以用來彌補邏輯漏洞

這樣看下來，邏輯很簡單，那為什麼在GMAT考試中會覺得難呢？一是英語的閱讀能力影響了理解分析，二是因為GMAT的邏輯鏈會更加複雜。第一個問題需要考生提高閱讀能力，第二個問題可以通過多做GMAT邏輯題，歸納總結經驗來提高。

下面我們看一道GMAT試題：

Scientists are discussing ways to remove excess carbon dioxide from the
atmosphere by increasing the amount that is absorbed by plant life. One plan to accomplish this is to establish
giant floating seaweed farms in the oceans.
When the seaweed plants die, they will be disposed of by being burned
for fuel.

Which of the following, if true, would indicate the most serious
weakness in the plan above?

Some areas of ocean in the Southern
Hemisphere do not contain sufficient nutrients to support large seaweed
farms.
When a seaweed plant is burned, it releases
an amount of carbon dioxide comparable to the amount it has absorbed in
its lifetime.
Even if seaweed farms prove effective, some
people will be reluctant to switch to this new fuel.
Each year about seven billion tons of carbon
dioxide are released into the atmosphere but only about five billion tons
are absorbed by plant life.
Seaweed farms would make more money by
farming seaweed to sell as nutritional supplements than by farming seaweed
to sell as fuel.

解題步驟

1. 讀題干，找出Facts Conclusion

Facts: （1）通過讓植物吸收更多 carbon dioxide來降低空氣中carbon dioxide的量

（2）計劃之一是在海里種giant floating seaweed

（3）seaweed plants 死後，會作為燃料燒掉

Conclusion: 在海里種giant floating
seaweed 可以減輕excess carbon dioxide from the atmosphere.（註：本題中並沒有用到conclude, thus, therefore等明顯表示conclusion的詞語，但是題干中conclusion非常的明確）。

2. 分析從Facts推導到Conclusion的過程中的邏輯漏洞

題干中的邏輯鏈可能有以下幾個方面的問題：

(1) 萬一 giant floating seaweed 不太能absorb carbon dioxide，計劃就行不通了

(2) 如果giant floating seaweed 吸收的並沒有比釋放的少，計劃就行不通了

3. 看問題，根據第二步發現的問題，找出相應的解答

Which of the following, if true, would indicate the most serious
weakness in the plan above?

根據上一步的分析，答案為When a seaweed plant is burned, it releases an amount of carbon dioxide
comparable to the amount it has absorbed in its lifetime.

再來一題。

In general, jobs are harder to get in times of economic recession
because many businesses cut back operations.
However, any future recessions in Vargonia will probably not reduce the
availability of teaching jobs at government-funded schools. This is because Vargonia has just introduced
a legal requirement that education in government-funded schools be available,
free of charge, to all Vargonian children regardless of the state of the
economy, and that current student-teacher ratios not be exceeded.

Which of the following, if true, most strengthens the argument?

The current
student-teacher ratio at Vargonia』s government-funded schools is higher
than it was during the most recent period of economic recession.
During
recent periods when the Vargonian economy has been strong, almost 25
percent of Vargonian children have attended privately funded schools, many
of which charge substantial fees.
Nearly 20
percent more teachers are currently employed in Vargonia』s
government-funded schools than had been employed in those schools in the
period before the last economic recession.
Teachers in
Vargonia』s government-funded schools are well paid relative to teachers in
most privately funded schools in Vargonia, many of which rely heavily on
part-time teachers.
During the
last economic recession in Vargonia, the government permanently closed a
number of the schools that it had funded.

1. 讀題干，找出Facts Conclusion

Facts: (1) 一般來說，經濟差，工作少（註：在本題中沒有實質用處）

(2) Vargonia 法律規定不管經濟如何government-funded schools 免費向所有Vargonian children提供教育而且目前的 student-teacher ratios 不能被超過。

Conclusion：未來經濟危機， Vargonia government-funded schools不會降低老師的招聘數量。

2. 分析從Facts推導到Conclusion的過程中的邏輯漏洞

如果經濟危機時，公立學校的學生人數少了，那麼在滿足目前的
student-teacher ratios的前提下，需要的老師人數也會相應減少

3. 看問題，根據第二步發現的問題，找出相應的解答

Which of the following, if true, most strengthens the argument?

根據上一步的分析，如果要strengthen那麼就應該彌補漏洞，即：經濟危機時，公立學校學生人數應該增多。答案為During recent periods when the Vargonian economy has been strong,
almost 25 percent of Vargonian children have attended privately funded schools,
many of which charge substantial fees. 經濟好的時候，25%的學生讀昂貴的私立學校è經濟不好的時候這些學生中會有一部分轉到公立學校è公立學校學生增多è招聘更多老師

【GMAT邏輯】GMAT邏輯解題思路（二）Conclusion/boldface

之前在【GMAT邏輯】GMAT邏輯解題思路（一）Assumption/weaken/strengthen中介紹了Assumption/weaken/strengthen題型的解題方法，這類題型大概佔到GMAT邏輯題的70%-80%。今天要講的是剩下20%-30%的conclusion以及boldface題型。

首先重複一下之前的定義：

Facts：題干中給出的信息（它們一定是正確的）

Conclusion：題干中由Facts推出的結論

【Conclusion】題型

Conclusion題型中，題干中只有Facts沒有Conclusion,
問題則是「通過題乾的facts,
我們能推出什麼Conclusion」。
不同於Assumption/weaken/strengthen題需要我們去尋找facts到conclusion的邏輯漏洞，Conclusion題需要我們將facts之間的關係理清楚，推出相應的結論。

舉幾個中文例子：

1. 題干（facts）：上海的面積小於北京的面積，而且上海的人口密度小於北京的人口密度

&<面積乘以密度等於總人口&>

結論:
上海的總人口小於北京的總人口

2. 題干（facts）:
小明比小紅長得高，小王比小紅小明都長得高

&< 身高：小明&>小紅
以及小王&>小紅，
小王&>小明&>

結論：身高：小王&>小明&>小紅

3. 題干（facts）：研究表明，絕大多數情況下教育程度越高，人越有禮貌；Lily高中畢業，Lucy大學畢業

& Lily 教育程度；教育程度與禮貌，絕大多數時候正相關&>

結論：It』s
likely that Lucy is more polite than Lily (注意題干中給出的是一個general的情況，所以我們只能說有很有可能lucy比Lily更禮貌，但不是Lucy一定比Lily更有禮貌)。

所以總結一下conclusion題的解題思路：

1. 找出題目中的每一個facts

2. 在不加入任何其他條件的情況下，通過這些facts可以推出哪些conclusion

下面看幾道GMAT例題：

1. Parasitic wasps
lay their eggs directly into the eggs of various host insects in exactly the
right numbers for any suitable size of host egg. If they laid too many eggs in
a host egg, the developing wasp larvae would compete with each other to the
death for nutrients and space. If too
few eggs were laid, portions of the host egg would decay, killing the wasp
larvae.

Which of the
following conclusions can properly be drawn from the information above?

(A) The size of the
smallest host egg that a wasp could theoretically parasitize can be determined
from the wasp"s egg-laying behavior.

(B) Host insects lack
any effective defenses against the form of predation practiced by parasitic
wasps.

(D) Failure to lay
enough eggs would lead to the death of the developing wasp larvae more quickly
than would laying too many eggs.

(E) Parasitic wasps
use visual clues to calculate the size of a host egg.

解題步驟：

1. 找出題目中的每一個facts

a) parasitic wasp 把卵產在host
insects的卵中，而且根據host 的卵的大小，parasitic
wasps 會相應的調整產卵的數量（exactly
right number）;

b) 如果產卵過多，
幼蟲會因為營養和空間compete;

c) 如果產卵過少，host
eggs 會腐爛，殺死wasp的幼蟲

2.在不加入任何其他條件的情況下，通過這些facts可以推出哪些conclusion

facts b)和c)都是在具體的解釋facts a) 即為什麼wasps 產卵的數量必須跟host eggs大小保持一致的關係(exactly
right number)。

所以可以推出的conclusion為：
numbers of parasitic wasps eggs ó size of
host eggs。因此正確選項為A（因為知道了wasp』s
egg-laying behavior 可以知道wasp 一次最少的產卵數量，再根據上面的conclusion從而知道相對應的host egg的大小），其他選項文中沒有提到。

2. A company"s two
divisions performed with remarkable consistency over the past three years: in each of those years, the pharmaceuticals
division has accounted for roughly 20 percent of dollar sales and 40 percent of
profits, and the chemicals division for the balance.

Which of the
following can properly be inferred regarding the past three years from the
statement above?

(A) Total dollar
sales for each of the company"s divisions have remained roughly constant.

(B) The
pharmaceuticals division has faced stiffer competition in its markets than has
the chemicals division.

(D) The product mix
offered by each of the company"s divisions has remained unchanged.

(E) Highly profitable
products accounted for a higher percentage of the chemicals division"s sales
than of those of the pharmaceuticals division.

解題步驟：

1. 找出題目中的每一個facts

a)過去三年，pharmaceuticals
division 佔到公司20%的銷量+40%的利潤；

b)過去三年，chemicals
division佔到公司80%的銷量+60%的利潤

2.在不加入任何其他條件的情況下，通過這些facts可以推出哪些conclusion

利潤率=利潤/銷量

所以可以推出的conclusion為：
pharmaceutical division 利潤率&>chemicals
division 利潤率。因此正確答案選擇C，其他選項文中沒有提到。

3. When a polygraph
test is judged inconclusive, this is no reflection on the examinee. Rather, such a judgment means that the test
has failed to show whether the examinee was truthful or untruthful. Nevertheless, employers will sometimes refuse
to hire a job applicant because of an inconclusive polygraph test result.

Which of the
following conclusions can most properly be drawn from the information above?

(A) Most examinees
with inconclusive polygraph test results are in fact untruthful.

(B) Polygraph tests
should not be used by employers in the consideration of job applicants.

(D) A polygraph test
indicating that an examinee is untruthful can sometimes be mistaken.

(E) Some employers
have refused to consider the results of polygraph tests when evaluating job
applicants.

解題步驟：

1. 找出題目中的每一個facts

a)如果測試結果是inconclusive,
那麼測試結果不能說明被測試的人是否誠實；

b)然而，有時候有的公司會拒絕那些測試結果是inconclusive的人

2.在不加入任何其他條件的情況下，通過這些facts可以推出哪些conclusion

è如果測試結果inconclusive，測試人不誠實，公司拒絕的對；

如果測試結果inconclusive，測試人誠實，公司拒絕的不對

所以可以推出的conclusion為：如果公司只要遇到inconclusive的結果就拒絕人，對於誠實的求職者來說是不公平的。因此正確選項為C，其他選項文中沒有提到。

4. United States
hospitals have traditionally relied primarily on revenues from paying patients
to offset losses from unreimbursed care.
Almost all paying patients now rely on governmental or private health
insurance to pay hospital bills.
Recently, insurers have been strictly limiting what they pay hospitals
for the care of insured patients to amounts at or below actual costs.

Which of the
following conclusions is best supported by the information above?

(A) Although the
advance of technology has made expensive medical procedures available to the
wealthy, such procedures are out of the reach of low-income patients.

(B) If hospitals do
not find ways of raising additional income for unreimbursed care, they must
either deny some of that care or suffer losses if they give it.

(C) Some patients
have incomes too high for eligibility for governmental health insurance but are
unable to afford private insurance for hospital care.

(D) If the hospitals
reduce their costs in providing care, insurance companies will maintain the
current level of reimbursement, thereby providing more funds for unreimbursed
care.

(E) Even though
philanthropic donations have traditionally provided some support for the
hospitals, such donations are at present declining.

解題步驟：

1. 找出題目中的每一個facts

a) 有史以來，美國醫院通過收取付錢病人的錢來補償不付錢的病人

b) 現在，幾乎所有付錢病人的錢都來自於醫療保險

c) 醫保只會付給醫院成本或者低於成本的錢

2.在不加入任何其他條件的情況下，通過這些facts可以推出哪些conclusion

è從a)可以推出，以前付錢的病人支付的錢&>他們接受的醫療服務的成本（否則也不存在用他們的錢補貼別人的情況了）

從b)c)可以推出，現在付錢病人支付的錢&<=他們接受的醫療服務的成本

所以可以推出的conclusion是以前醫院通過付錢病人賺點錢，現在也沒有辦法通過付錢病人賺錢了。因此正確選項為B：付錢病人端已經沒錢賺了，如果不付錢那邊還不改一改，那肯定虧錢。其他選項文中沒有提到。

5. To protect certain
fledgling industries, the government of country Z banned imports of the types
of products those industries were starting to make. As a direct result, the cost of those
products to the buyers, several export-dependent industries in Z, went up,
sharply limiting the ability of those industries to compete effectively in
their export markets.

Which of the
following can be most properly inferred from the passage about the products
whose importation was banned?

(A) Those products
had been cheaper to import than they were to make within country Z"s fledgling
industries.

(B) Those products
were the ones that country Z was hoping to export in its turn, once the
fledgling industries matured.

(D) Those products
had become more and more expensive to import, which resulted in a foreign trade
deficit just before the ban.

(E) Those products
used to be imported in very small quantities, but they were essential to
country Z"s economy.

解題步驟：

1. 找出題目中的每一個facts

a)為了保護某些行業，Z國不允許進口這些行業生產的同類產品（假設為產品A）（即：需要這些產品，只能買國產，沒有進口）

b)由於這個政策，這些產品A的買家的成本急劇上升，使得這些買家生產的產品（假設為產品B）在國際市場價格上漲，出口沒有優勢（原文中的句子比較繞，考生需要注意理解句意）

2.在不加入任何其他條件的情況下，通過這些facts可以推出哪些conclusion

a)是b)的原因，即不讓進口A，導致購買A的成本增加。因此可以推出的conclusion是A的進口價比國內產的價格便宜。因此答案為A，其他選項文中沒有提到。注意：這道題跟之前的題目稍有不同的地方是，之前的題目是從前往後推順著推，而這道題是從後往前推倒著推，需要大家多多體會。

【Boldface】題型

一般情況下一場GMAT考試，出現boldface題的概率較小，出現了也就一題左右。Boldface題一般情況下題干中會既包含facts和conclusion，所以題干通常比較長。解題思路包括以下兩點：

1. 劃線句子在文中起什麼作用

2. 劃線句子之間是什麼關係

下面講幾個例子：

1.
Astronomer: Observations of the Shoemaker-Levi comet on its collision course
with Jupiter showed that the comet broke into fragments before entering
Jupiter"s atmosphere in 1994, but they did not show how big those fragments
were. In hopes of gaining some indication of the fragments" size, astronomers
studied spectrographic analyses of Jupiter"s outer atmosphere. These analyses revealed unprecedented traces
of sulfur after the fragments" entry. The fragments themselves almost
certainly contained no sulfur, but many astronomers believe that the cloud
layer below Jupiter"s outer atmosphere does contain sulfur. Since sulfur
would have seeped into the outer atmosphere if comet fragments had penetrated
this cloud layer, it is likely that some of the fragments were at least
large enough to have passed through Jupiter"s outer atmosphere without being
burned up.

In the
astronomer"s argument, the two portions in boldface play which of the
following roles?

(A) The
first presents a circumstance for which the astronomer offers an explanation;
the second is part of that explanation.

(B) The
first acknowledges a consideration that weighs against the conclusion of the
argument; the second is that conclusion.

(C) The
first acknowledges a consideration that weighs against the conclusion of the
argument; the second provides evidence in support of that conclusion.

(D) The
first provides evidence in support of the conclusion of the argument; the
second acknowledges a consideration that weighs against that conclusion.

(E) The first is a judgment advanced in support of the conclusion of the
argument; the second is that conclusion.

解題思路：

1. 劃線句子在文中起什麼作用

第一句講述的是一個事實以及一個猜測，第二句是一個明顯的結論（這裡的結論並不僅僅是指conclusion，也可以是explanation,
hypothesis，claims,
judgement等，只是說從結構上來說是作者通過前面給出的信息推出的一個結論）.

2. 劃線句子之間是什麼關係

第一個句子是第二個句子得出結論的一個依據。

因此正確答案為E。

(A) The
first presents a circumstance for which the astronomer offers an explanation;
the second is part of that explanation.（astronomers並沒有給第一句話中的circumstance 解釋）

(B) The
first acknowledges a consideration that weighs against the conclusion of the
argument; the second is that conclusion.（weighs
against 錯誤，這兩句話並沒有矛盾）

(C) The
first acknowledges a consideration that weighs against the conclusion of the
argument; the second provides evidence in support of that conclusion.（與B相同，這兩句話並沒有矛盾）

(D) The
first provides evidence in support of the conclusion of the argument; the
second acknowledges a consideration that weighs against that conclusion. （與B相同，這兩句話並沒有矛盾）

(E)
The first is a judgment advanced in support of the conclusion of the argument;
the second is that conclusion.

2. Plant
scientists have used genetic engineering on seeds to produce crop plants that
are highly resistant to insect damage. Unfortunately, the seeds themselves
are quite expensive, and the plants require more fertilizer and water to grow
well than normal ones. Thus, for most farmers the savings on pesticides
would not compensate for the higher seed costs and the cost of additional
fertilizer. However, since consumer demand for grains, fruits, and
vegetables grown without the use of pesticides continues to rise, the use of
genetically engineered seeds of this kind is likely to become widespread.

In the
argument given, the two portions in boldface play which of the following
roles?

(A) The
first supplies a context for the argument; the second is the argument"s main
conclusion.

(B) The
first introduces a development that the argument predicts will have a certain
outcome; the second is a state of affairs that the argument denies will be part
of that outcome.

(C) The
first presents a development that the argument predicts will have a certain
outcome; the second acknowledges a consideration that weighs against that
prediction.

(D) The
first provides evidence to support a prediction that the argument seeks to
defend; the second is that prediction.

(E) The
first and the second each provide evidence to support the argument"s main
conclusion.

解題思路：

1. 劃線句子在文中起什麼作用

第一句講述的是一個事實，用於支持後一句話；第二句話講述了另一個事實，用於支持同一句話中出現的結論。

2. 劃線句子之間是什麼關係

這兩句話支持的結論之間有明顯的對立關係。

因此正確答案為C。

(A) The
first supplies a context for the argument; the second is the argument"s main
conclusion(第一句話講述的事實，不存在contest).

(B) The
first introduces a development that the argument predicts will have a certain
outcome; the second is a state of affairs that the argument denies will be part
of that outcome.(第二句話中出現的outcome並沒有被deny)

(C) The first presents a development that the
argument predicts will have a certain outcome; the second acknowledges a
consideration that weighs against that prediction.

(D) The
first provides evidence to support a prediction that the argument seeks to
defend; the second is that prediction. (第一第二句之間應該是對立關係，而不是相互支持關係)

(E) The
first and the second each provide evidence to support the argument"s main
conclusion.（第一第二句支持的是不同的觀點）

3. During
the past year, Pro-Tect Insurance Company"s total payout on car-theft claims
has been larger than the company can afford to sustain. Pro-Tect cannot reduce the number of
car-theft policies it carries, so it cannot protect itself against continued
large payouts that way. Therefore,
Pro-Tect has decided to offer a discount to holders of car-theft policies whose
cars have antitheft devices. Many policyholders will respond to the discount by
installing such devices, since the amount of the discount will within two years
typically more than cover the cost of installation. Thus, because cars with
antitheft devices are rarely stolen, Pro-Tect"s plan is likely to reduce its
annual payouts.

In the
argument above, the two portions in boldface play which of the following
roles?

(A) The
first and the second are both evidence offered by the argument as support for
its main conclusion.

(B) The
first presents a problem a response to which the argument assesses; the second
is the judgment reached by that assessment.

(C) The
first is the position the argument seeks to establish; the second is a judgment
the argument uses to support that position.

(D) The
first is a development that the argument seeks to explain; the second is a
prediction the argument makes in support of the explanation it offers.

(E) The first
presents a development whose likely outcome is at issue in the argument; the
second is a judgment the argument uses in support of its conclusion about that
outcome.

解題思路：

1. 劃線句子在文中起什麼作用

第一句講述的是一個事實，以及這個事實帶來的後果；第二句話提到新的政策導致的後果，是題乾的conclusion.

2. 劃線句子之間是什麼關係

這兩句話都是針對同一個問題，即公司annual payout的問題。第一句話中提到的部分使得annual payout不能減少，第二句話說到的部分使得annual payout可以減少。同時文中therefore, thus 都表明第一句話中出現的問題，導致了第二句話的出現。

因此正確答案為B。

(A) The
first and the second are both evidence offered by the argument as support for
its main conclusion. (第一句話不support
conclusion)

(B) The first presents a problem a response
to which the argument assesses; the second is the judgment reached by that
assessment.

(C) The
first is the position the argument seeks to establish; the second is a judgment
the argument uses to support that position.（作者並沒有想要establish第一句，而且第二句也沒有用來support第一句）

(D) The
first is a development that the argument seeks to explain; the second is a
prediction the argument makes in support of the explanation it offers.（第一句是一個事實，作者沒有explain）

(E) The first
presents a development whose likely outcome is at issue in the argument; the
second is a judgment the argument uses in support of its conclusion about that
outcome.(第一句話是事實，結果是肯定的，不存在 outcome
at issue;第二句話本身就是conclusion,
而不是support conclusion)

到這裡GMAT邏輯已經全部講完了，再次強調邏輯並不難，同學們認真對照OG的解答，多練習反思，一定可以掌握GMAT邏輯的技巧。與其把GMAT邏輯當成考試，不如當成智力測試題，讓複習的過程更加有趣。

邏輯思維這塊，還是非常重要的，邏輯這塊好一點，考gmat就非常輕鬆了。我是學習GMAT的時候，別人推薦用新東方的700分課程，這個提分非常好，如果有要的，我這邊可以給網課資源的，很划算哦。

總體原則是：不要腦補不存在的信息；每一個題目提供的信息點都有用；推理要嚴謹，100%會發生的情況，不要"感覺"合理；邏輯鏈上沒有GAP；90%的錯誤答案都錯在無關。

GMAT 750 verbal 40

個人覺得gmat的cr是非常淺顯易懂的那種。一個正常人哪怕沒有系統學過任何邏輯知識。給他gmat邏輯題做，做對的幾率也是非常大的！所以，重點之一，是不要想多了。要有正確的邏輯總思路。別鑽牛角尖，別歪了。有時候很愛想多，總是容易多推理一步，使得一個選項看起來更對了。再一個最最重要的就是，gmat的答案只有最優選項。這點要牢記。所以verbal的選項，一定要全都讀！我看到有的地方建議說為了提高速度，做verbal看到正確選項要秒選。這樣真的非常危險。我就是因為剛開始這樣做題所以做錯了。gmat有兩個都合理的選項是可以的。但是裡面一定有一個最優選項。至於另一個你覺得也合理的，往往可能是你自己思維上的一個慣性導致你覺得也可以，導致你發現不了大錯誤（其實按照gmat邏輯這個選項是欠缺的）。然而在一起比較的時候，最優選項就會浮現出來。verbal時間的節省只能是因為你做題做多了你能快速判斷一個選項的對錯，絕不能是靠漏看一個選項而得出的。verbal的所有選項必須都清楚後再做出判斷。

強烈推薦看bible，非常正確的結題思路。比如開篇就說了先看題目再看題乾的方法是愚蠢的。我看到很多其他地方還推薦該先看題目判斷題型呢！

思維方式和我們很不同，通過做題去體會，邏輯有的考的很細節，總的原則就是以題目為本，不要超出原文的邏輯範疇

GMAT主要考2個：

決策思維（想要做決策的前提是能快速找到決策標準，這需要快速抓取關鍵信息的能力，有了決策標準，進行有關和無關對比排除）

全局觀（GMAT考試是一個管理問題，時間和能力資源固定的前提下，如何能最大化的輸出？這個是很多學生的問題，單項做的挺好，合在一起考試就亂套，這個和企業管理一個道理，管理裡面最難的問題就是協同，當然GMAT沒那麼難，不過GMAT確實是一個很考全局觀的考試）

2016年上海GMAT培訓機構對比分析

隨著出國留學的日益趨向大眾化，其中就業率偏高且無入學門檻（當然除了專業會計外）商科留學更加是受到大眾青睞。而如果留學美國/法國商科，或英國高等學府之類的，都需要GMAT成績，所以近幾年來GMAT培訓機構就像如韭菜的美女一樣，割完一茬還長一茬，茬茬生生不息。

我是做金融的，所以對於數據之類的比較敏感，現在想要申請MBA，因為平時工作時間緊，所以就想快刀斬亂麻，找個靠譜的培訓班，學習下他們的做題方法，畢竟應試教育已經遠離我很多年。而且據說長時間、高難度的自適應機試，也應該模考聯繫下。借鑒了下前輩整理的GMAT培訓機構的分析對比圖（附下表二），但是這些內容都不是我想要的，我更加關心的是這幾個機構在我預期中的服務是否都含有，所以自己根據自己的需求也做了個對比數據，如下圖：

新東方：新東方年代悠久品牌效應大，主要營業方向為語言培訓，所以在GMAT培訓方面服務體系不算完善，沒有類似於炙手可熱的測評/模考/答疑等服務；人數不齊不開班，所以開班時間不固定；在各地開設的課程內容不同，有的較單一；班型一般為25-50人的大班授課，價格便宜，但是應該上課體驗不佳；沒有相應的名師，師資力量也不足；諮詢老師推薦VIP課程，但是對於具體的課時設置含糊不清，腦補VIP課程不成熟；沒有比較成熟的內部資料。後期服務的話幾乎無；

博智：管衛東名師效應，但是和英吉/唐瑛的授課費用較貴；每月各地區開班一次，大班教學，不講數學，授課時間固定，面授4天；課程收費價格和學生的基礎有關；後期服務時間長達半年，可在全國各校區聽課，定期提供在線答疑服務，模考系統（前6個月免費，後6個月180元/月，只給正確率不出分），內部學員會不定期組織活動；VIP一對一按照不同的老師授課會有不同的標準。

海翔：成立於2008年，只做GMAT培訓，應該說是小有積累的術業專攻；班型多樣化，模塊課程可自由組合，小班授課，固定開課，價格適中；全國來講都算是完善的服務系統，但是不知道具體使用情況如何；服務期一年，可重複聽課，設置有GMAT獎學金；《GMAT語文考試全程指南》教材是正式出版物；後期服務長達一年，模考系統和論壇學員免費使用，內部學員不定期組織活動；教學服務系統和教學輔助系統完善。