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GMAT邏輯講義

時(shí)間:2008-04-27 19:14:00   來源:太傻網(wǎng)     [字體: ]
GMAT邏輯講義

  吳強(qiáng)

  一、歸納題:從上到下(從原文到答案)

  ①讀題1)注意條件句,如if, as long as等,例第二冊(cè)P203 (20)

  2)注意有沒有否絕對(duì)化詞,如only,any,no, solely等

  3)注意有沒有數(shù)學(xué)上的等式、不等式關(guān)系或比例(percent, proportion)

  等,

  例第二冊(cè)第二冊(cè)P117⒂、P126⒆、P169(1)、P248(14)

  ②判斷答案的原則:(1)答案中不能出現(xiàn)原文中沒有的新概念(包括新的動(dòng)詞、形容詞

  、

  名詞等,但是需要同義詞的出現(xiàn))

  (2)若原文在某一信息點(diǎn)上沒有絕對(duì)化概念,那么答案中也沒

  有

  (3)不能出現(xiàn)新的比較

  (4)答案不能和原文信息相違背。

  例題:第二冊(cè)P115⑽P116⑾P123⑼P126⒅

 、弁茖(dǎo)結(jié)構(gòu)

  例題第二冊(cè)P122④,講義section 1(19題)

  2)理解命題及常用表達(dá)(這一知識(shí)點(diǎn)需要好好把握,不僅僅在歸納題中有用,

  在邏輯

  描述題中,邏輯結(jié)構(gòu)一致性,對(duì)上文的批評(píng)等問法中

  都出現(xiàn))

  原命題和逆否命題為等價(jià)命題,逆命題和否命題為等價(jià)命題

  (A→B+C,逆否命題為~B/~C→~A), (A+B→C,則其逆否命題為~C

  →~A/~B)

  II. unless :=if not即not A unless B表達(dá)為A→B

  A unless B表達(dá)為非A→B

  only if: A only if B表達(dá)為A→B

  if only: A if only B表達(dá)為B→A

  A is necessary to B: B→A

  Whenever, whoever, wherever :=if

  二、Weaken和Support演繹題型(從下到上,即從答案到原文)

  weaken support

  Reasoning

  Premise(前提),Conclusion(結(jié)論),Reasoning(推理過程,前提到結(jié)論的思維

  變遷)

  演繹題所面臨的是一個(gè)“待評(píng)價(jià)的推理”,也就是從前提到結(jié)論的這個(gè)推理是否能夠

  成立我是不知道的,我需要對(duì)它進(jìn)行評(píng)價(jià)。根據(jù)問題的不同問法,確定不同的解題態(tài)度

  ,問支持,就找一個(gè)選項(xiàng)說它可能對(duì),問反對(duì),找一個(gè)選項(xiàng)說它不一定對(duì),問假設(shè)考慮

  使結(jié)論成立需要什么,哪一個(gè)是使其成立的一個(gè)必要條件。

  1.如何正確理解weaken , support

  ①支持:(support),將答案放在論據(jù)和結(jié)論之間,對(duì)原文推理或者結(jié)論有支持作用就可

  以,

  所以既可非充分又可非必要

  ②駁斥:(weaken),將答案放在論據(jù)和結(jié)論之間,對(duì)原文推理或者結(jié)論有駁斥作用就

  可以,

  所以也是既可非充分又可非必要

 、廴绾卫斫獬浞趾捅匾

  1.充分:所謂充分條件就是僅有這條件就足以帶來結(jié)果,不需考慮別的條件了。

  它是誰成立,誰一定也成立,比如A→B,如果A成立,那么一定有B

  2.必要:所謂必要條件就是沒有這個(gè)條件結(jié)果一定不對(duì)。

  2.前因后果結(jié)構(gòu)

  推理中的前提和結(jié)論在大多數(shù)情況下用因果關(guān)系來表示,根據(jù)因果關(guān)系中的結(jié)果成立

  不成立我們分為兩種邏輯結(jié)構(gòu),前因后果結(jié)果和Causal Explanations結(jié)構(gòu),以后講的答

  案方向點(diǎn)區(qū)別并不大,但是我們?yōu)榱死诶斫膺M(jìn)行這個(gè)分類

  前因后果結(jié)構(gòu)表示:(A——B)

  從這個(gè)原因是否能夠得到這個(gè)結(jié)果?(注意because, since, for等原因引導(dǎo)詞

  )

  這個(gè)方法是否能夠達(dá)到這個(gè)目的?(注意by引導(dǎo)方法,To的不定式引導(dǎo)目的)

  從這個(gè)條件是否能夠得到這個(gè)結(jié)論?(注意if,when, as long as等引導(dǎo)條件

  )

  ★注意上面的結(jié)果、結(jié)論到底能不能夠成立,目的到底能不能夠達(dá)到,還不確定

  。

  駁斥、支持方向:

  A方法可行,P122(7)

  A-B之間P113(3)、P116(12)

  A之外因素的影響B(tài) P113(2)、P123(11)

  直接對(duì)B說講義Section 1第4題

  3.Causal Explanations

  a.對(duì)一個(gè)事實(shí)的發(fā)生、一個(gè)現(xiàn)象的存在,一個(gè)研究的發(fā)現(xiàn),提出一種解釋

  也就是為什么這個(gè)事實(shí)會(huì)發(fā)生呢?為什么這個(gè)現(xiàn)象會(huì)存在呢?是這個(gè)原因?qū)е碌?/p>

  b.從一個(gè)已知的,已經(jīng)發(fā)生的事實(shí),已經(jīng)存在的現(xiàn)象中得到一個(gè)結(jié)論,這個(gè)結(jié)論其實(shí)還是

  對(duì)上面的事實(shí)發(fā)生、現(xiàn)象存在做出了一種解釋

  ★注意上面的結(jié)果、事實(shí),現(xiàn)象都是已經(jīng)發(fā)生,已經(jīng)成立了,問到底是不是這個(gè)原因?qū)?/p>

  致的,

  這也是Causal Explanation結(jié)構(gòu)和前因后果結(jié)構(gòu)最本質(zhì)的區(qū)別,務(wù)必仔細(xì)體會(huì)。

  Causal Explanation結(jié)構(gòu)的典型引導(dǎo)詞:result、due to、reason、attribute to、

  hypothesize、

  the explanation is、be responsible for

  、

  把這個(gè)事實(shí)當(dāng)作B,把這個(gè)原因解釋當(dāng)作A,

  答案方向:這個(gè)原因和結(jié)果之間的關(guān)系?(B-A之間)

  有沒有別的原因來對(duì)上面的事實(shí)、現(xiàn)象、研究發(fā)現(xiàn)作出解釋(A之外的其他

  原因)

  支持:直接:就是這原因?qū)е陆Y(jié)果,具體還可以表現(xiàn)為沒有這個(gè)原因就沒有這個(gè)結(jié)果。

  例題:講義Section 1第1題,P201(12)

  間接:沒有別的原因解釋上面的事實(shí)或現(xiàn)象

  駁斥:直接:原因和結(jié)果無關(guān),具體表現(xiàn)為有這個(gè)原因沒有這個(gè)結(jié)果或者沒有這個(gè)原因

  有這個(gè)結(jié)果

  例題:P114(7), P115(9)

  間接:還有別的原因存在解釋上面的事實(shí)或現(xiàn)象P124(13)

  如何統(tǒng)一兩種結(jié)構(gòu)的答案方向?

  4.Weaken, Support讀題:

  1)重點(diǎn)是找出原因和結(jié)果兩句話,如果沒有任何原因指示詞,那么重點(diǎn)在

  結(jié)論,緊

  靠結(jié)論因果詞(therefore ,thus)前面的往往就是原因

  2)對(duì)to的不定式要讀出(往往表示為對(duì)一個(gè)目的提出一個(gè)方法)

  3)對(duì)any, all, none, everyone, each, no, in general, on the whole

  等

  詞需注意,因可能會(huì)為范圍差異

  4)對(duì)only, solely加以注意,例:第四冊(cè):P18⑿

  5)對(duì)動(dòng)詞的程度修飾,例:第四冊(cè):P7⑥

  5.一些輔助的類型

  范圍差異、數(shù)據(jù)得結(jié)果、因果順序、比較原則

  三:“Assumption”題型

  假設(shè)定義:使結(jié)論成立的必要條件

 、僮x題:和weaken ,support讀題方法完全一樣,再注意when、if等詞語

 、诖鸢阜较颍

  前因后果結(jié)構(gòu)

  1)因果關(guān)系差異概念的橋梁作用(A-B之間)

  例題:P115(8)、P122(5)、P200(7)、P202(15)、P248(12)、P249(16

  )

  2)A可行性或者原因有意義:P228(9)、P246(7)

  3)沒有其他的因素來影響這個(gè)結(jié)果或者結(jié)論P(yáng)248(12)、P250(18)

  Causal Explanations:

  1)沒有這個(gè)原因就沒有這個(gè)結(jié)果(兩者之間)

  3)沒有其他的原因來解釋上面的事實(shí)或者現(xiàn)象P173(16)、P229(13)

  ★注意此類假設(shè)其答案中,很可能會(huì)有否定詞或類似否定概念出現(xiàn)

  注意:和weaken、support一樣,這兩種結(jié)構(gòu)的答案方向完全可以統(tǒng)一

  四:“evaluate”題型

  1.定義:對(duì)某個(gè)問題兩方面的回答(yes and no)或者某個(gè)信息兩方面的回答,對(duì)原

  文推理如果

  一方面回答起到支持作用,則另一方面回答起到駁斥作用,如果一方面回答起到

  駁斥作

  用,則另一方面回答起到支持作用,這個(gè)問題或者信息就對(duì)原文有評(píng)價(jià)作用。

  ★注意一定是yes and no回答都起到作用,如果僅僅一方面回答起到作用,則

  不是評(píng)價(jià)

  2.答案方向:1)直接說,結(jié)果和原因之間有沒有關(guān)系(A-B)例:第二冊(cè)P172(10)、

  P198(3)

  2)A是否可行或者有意義。講義section 1(11題)

  3)間接性答案:除A之外是否還有別的因素影響B(tài),例:第四冊(cè)P104⑨

  或者有沒有其他的原因來解釋原文中存在的事實(shí)或者現(xiàn)象

  注意:evaluation、assumption和weaken, support的統(tǒng)一

  五:解釋現(xiàn)象

  1.解釋result, situation等,統(tǒng)稱為解釋結(jié)果

  具體讀出要解釋什么,現(xiàn)象是什么,解題要點(diǎn):抓住要解釋的對(duì)象,具體發(fā)生了什么

  變化

  2.解釋矛盾,找一個(gè)選項(xiàng)說明為什么會(huì)存在這種矛盾,解題主要抓住區(qū)別點(diǎn)

  3.答案要明確,滿足無推導(dǎo)、無充分性。講義section 1(第20題)

  六.完成一段話“題型”

  找答案需滿足:1)在句子意思上滿足原文,特別是可將最后一句話補(bǔ)全

  2)答案必須和原文前半段描述有關(guān)系

  例:第二冊(cè):P60⑧P70④P201⒁

  七.“上文使用何種有疑問技術(shù)”題型(邏輯描述)

  并不是讓你找一個(gè)選項(xiàng)對(duì)上文推理進(jìn)行駁斥,也不是問原文推理的缺陷,而是讓你用邏

  輯描述的語言來描述一下原文的推導(dǎo)過程。

  例:第三冊(cè)P4 (17)第四冊(cè)P85⑨

  八、提高(由學(xué)生自己去訓(xùn)練培養(yǎng)對(duì)weaken support等題的感覺)

  1.Weaken:——求異2.Support:——求同

  所謂求同、求異就是答案和原文的一致或不一致,而不是答案中誰與誰一致或不一致,

  它要求既不要考慮原文的因果之間為什么會(huì)如此,也不要考慮答案中因果之間為什么會(huì)

  如此,更不可考慮此答案是如何使得對(duì)原文有支持或駁斥作用的,而僅僅辨認(rèn)在答案滿

  足和原文有關(guān)時(shí)是保持和原文一致還是不一致,這一點(diǎn)往往對(duì)于難題來講,特別還僅僅

  剩下兩個(gè)選項(xiàng)需要辨別的時(shí)候,更為有用

  例:“因?yàn)檫@兒有個(gè)人,所以螞蟻有兩條腿。”對(duì)這一論證的支持或駁斥不應(yīng)考慮為什

  么人和螞蟻有關(guān),而只考慮在答案中說有人或說螞蟻兩條腿的情況下,找其相同或不同

  就可以了,如“相鄰近處沒有人,螞蟻也有兩條腿”,在滿足說螞蟻有兩條腿時(shí)說的是

  沒有人,和上邊論述不一致,因此可weaken同理說“在鄰近處沒有人,螞蟻也就無兩條

  腿,”就有support作用,你所需做的僅僅是尋找相同或不同點(diǎn),而已,大家可由第

  三冊(cè)上P1②P2⑼P3⑿P5⒇P28③⑤P29⑿⒂P46⑥P47⑩⒀等題

  去理解weaken,由第二冊(cè)上P30⑾P31⒇P45④

  P48⒂等理解support.

  九、最后讀題

  GMAT改為機(jī)考后,邏輯題長(zhǎng)度明顯增加,對(duì)此除提高閱讀能力外(不是閱讀技巧)

  ,主要要做訓(xùn)練看對(duì)一段話中在僅讀一遍的情況下,究竟哪句話為結(jié)論,然后看出和結(jié)

  論相關(guān)的直接原因是什么,最后次要地看出和直接原因相關(guān)的性質(zhì)點(diǎn)中,原文提出過什

  么就可以了,但對(duì)于“歸納”題型只能學(xué)會(huì)一邊讀一邊思考原文的層次是什么,腦中將

  層次留下,無其他好方法。

  Section 1

  1. The town of Stavanger, Norway, was quiet and

  peaceful until the early 1960’s, when Stavanger

  became Norway’s center for offshore oil exploration.

  Between then and now, violent crime and vandalism

  in Stavanger have greatly increased. Clearly, these

  social problems are among the results of Stavanger’s

  oil boom.

  Which of the following, if it occurred between the

  early 1960’s and now, gives the strongest support

  to the argument above?

  (A) The people of Stavanger rarely regret that their

  town was chosen to be Norway’s center for

  offshore oil exploration

  (B) Norwegian sociologists expressed grave concern

  about the increase in violent crime and

  vandalism in Stavanger.

  (C) Violent crime and vandalism have remained low

  in Norwegian towns that had no oil boom.

  (D) Nonviolent crime, drug addiction, and divorce

  in Stavanger increased approximately as

  much as violent crime and vandalism did.

  (E) The oil boom necessitated the building of wider

  roads for the increased traffic in Stavanger.

  2. Since 1945 there have been numerous international

  confrontations as tense as those that precipitated the

  Second World War, and yet no large-scale conflict

  has resulted. To explain this, some argue that fear

  of enormous destruction such as the Second World

  War produced has had a dramatic deterrent effect.

  Which of the following, if true, most seriously

  weakens the deterrent theory mentioned above?

  (A) After the First World War, the fear of great

  future destruction was as intense as it was

  after the Second World war.

  (B) Psychologists have determined that the fear

  of retaliation tends to temper aggressiveness

  among human beings.

  (C) The Second World War was far less destructive

  than most people generally believe.

  (D) Fear of repeating the levels of destruction that

  the Second World War produced is as pervasive

  today as it was forty years ago.

  (E) Many of the international confrontations that

  have occurred since 1945 have involved countries

  that participated in the Second World War.

  3. A list of the fifteen operas most frequently performed

  in recent times includes no works by the nineteenth

  century German composer Richard Wagner. Although

  music producers tend to produce what audiences want,

  relative infrequency of performance probably does

  not indicate lack of popularity in Wagner’s case, since

  Wagner’s operas are notoriously expensive to perform

  on stage.

  Which of the following, if true, most strongly

  support the conclusion of the argument above?

  (A)The list of most frequently performed operas

  does not include operas produced by small

  amateur groups.

  (B)Some opera companies are backed by patrons

  who are willing to commit large sums of

  money insgroupsto enjoy lavish productions.

  (C)All of the fifteen most frequently performed

  operas of recent times are works that have

  been popular for at least 75 years.

  (D)More recordings have been produced recently of

  the works of Wagner than of the works of any

  other composer of opera.

  (E)Operatic works of all kinds have been increasing

  in popularity in recent years.

  4. V-shaped walled structures in central Asia

  were used by prehistoric hunters who drove

  hoofed animalssintosan enclosure at the point

  of the V. The central Asians who built these

  structures probably learned this hunting

  technique from invaders from southwest Asia,

  because the arrival of invaders from a region

  in southwest Asiaswheressimilar structures had

  long been used coincides roughly with the

  building of the earliest of such structures in

  central Asia.

  Which of the following, if true, most strengthens

  the argument?

  (A) Excavations in the central Asian region do

  not indicate whether invaders from

  southwest Asia settled permanently in

  central Asia.

  (B) The V-shaped structures in central Asia

  were roughly 70 meters long, whereas the

  similar structures in southwest Asia were

  usually over 300 meters long.

  (C) The walls of the structures in central Asia

  were made from earth, whereas the walls

  of the structures in southwest Asia

  were made of rock.

  (D) The earliest examples of V-shaped walled

  structures in central Asia were of an

  advanced design.

  (E) Some of the walled structures used for

  hunting in southwest Asia were built well

  after the earliest such structures were built

  in central Asia.

  5. The average age and racing experience of the drivers

  at the Indianapolis 500 automobile race increased

  each year between 1965 and 1980. The reason for

  the increase is that high-speed racing drivers were

  living longer than their predecessors. Race-car safety

  features that reduced the severity of crashes of the

  kind that formerly took drivers’lives were primarily

  responsible for the increase in the average age of the

  Indianapolis 500 competitors.

  Which of the following, if true, would be most likely

  to be part of the evidence used to show that safety

  features on the cars that protected drivers in major

  crashes were responsible for the increase in the

  average age of drivers at the Indianapolis race?

  (A) Younger drivers at high-speed racetracks

  were involved in major accidents at a

  slightly higher rate than were older drivers

  between 1965 and 1980.

  (B) Major accidents on high-speed racetracks

  occurred at about the same frequency in the

  years after 1965 as in the years before 1965.

  (C) The average age of drivers attempting to

  qualify for the Indianapolis 500 decreased

  slightly between 1965 and 1980.

  (D) Accidents on highways in the United States

  occurred at about the same frequency in the

  years after 1965 as in the years before 1965.

  (E) Other safety features, involving the condition of

  the racetrack and the uniforms worn by the

  drivers while driving, were adopted at

  Indianapolis between 1965 and 1980.

  6. Calvin: Fire insurance policies are disadvanta-

  geous to policyholders. The typical poli-

  cyholder always pays more in premiums

  than he or she collects in payments on

  policies.

  Lorraine: Yes, but policyholders are still right in

  thinking that it is to their advantage to

  hold an insurance policy. The peace of

  mind that comes fromshavingsan insurance

  policy is the main advantage to the poli-

  cyholder.

  Lorraine addresses Calvin’s argument by

  (A) Questioning the source of Calvin’s factual infor-

  mation

  (B) introducing a consideration neglected by

  Calvin’s argument

  (C) showing that Calvin’s argument assumes what

  it sets out to prove

  (D) challenging the truth of the evidence advanced

  in Calvin’s argument

  (E) showing the irrelevance of Calvin’s evidence to

  the conclusion he draws

  7.X: When a rare but serious industrial accident

  occurs, people respond by believing that such

  accidents are becoming more frequent. This

  belief is irrational. After all, being dealt four

  aces in a hand of poker, a rare event, hardly

  increases one’s chances of being dealt four aces

  in a future hand.

  Y: To the contrary, the belief is rational because it

  results in people’s sensing a danger to them-

  selves not previously sensed and taking precau-

  tionary actions to prevent similar accidents in

  the future.

  Y’s attempt to counter X’s claim is best described

  by which of the following?

  (A) It questions the aptness of the analogy drawn

  by X.

  (B) It makes apparent X’s failure to consider how

  people vary in their responses to a serious

  accident.

  (C) It shifts the basis for judging rationality to

  considerations of utility.

  (D) It offers an alternative explanation of why

  people form incorrect beliefs.

  (E) It challenges X’s assumption that the occur-

  rence of a single event is sufficient to change

  a belief.

  8.

  John: It is permissible and even advisable to

  execute criminals convicted of brutal

  murders. After all, a publicized execution

  can serve to deter heinous crimes and thus

  minimize suffering in the long run. Capital.

  punishment is a kind of societal self-defense.

  Mary: You are ignoring the prior issue of whether

  a state or society has the right to take

  anyone’s life. If there is no such right. then,

  the issue of whether capital punishment

  deters crime is irrelevant.

  If it were determined dial capital punishment does

  not serve to deter crime. John’s and Mary’s posi-

  tions would be affected in which of the following

  ways?

  (A) Neither John’s nor Mary’s position would be

  affected.

  (B) Both John’s and Mary’s positions would be

  weakened.

  (C) Mary’s position would be strengthened but

  John’s position would not be affected.

  (D) John’s position would be weakened but Mary’s

  position would not be affected,

  (E) John’s position would be weakened and Mary’s

  position would be strengthened.

  9. Excluding purchases by businesses, the average

  amount spent on a factory-new car has risen 30 per-

  cent in the last five years. In the average household

  budget, the proportion spent on car purchases has

  remained unchanged in that period. Therefore the

  average household budget must have increased by

  30 percent over the last five years.

  Which of the following is an assumption on which

  the argument relies?

  (A)The average number of factory-new cars pur-

  chased per household has remained unchanged

  over the last five years.

  (B)The average amount spent per car by businesses

  buying factory-new cars has risen 30 percent in

  the last five years.

  (C)The proportion of the average household budget

  spent on all car-related expenses has remained

  unchanged over the last five years.

  (D)The proportion of the average household budget

  spent on food and housing has remained

  unchanged over the last five years.

  (E)The total amount spent nationwide on factory-

  new cars has increased by 30 percent over the

  last five years.

  10. Editorial:

  Critics of nuclear power complain about the allegedly

  serious harm that might result from continued operation

  of existing nuclear power plants. But such concerns do

  not justify closing these plants;after all, their operation

  has caused no more harm than that caused by pollution

  generated by coal-and oil-burning power plants, the

  most important other sources of energy.

  Which of the following is an assumption on which the

  argument depends?

  (A) Existing nuclear power plants should be closed only

  if it can be conclusively demonstrated that their

  continued operation is likely to cause harm more

  serious than the harm their operation has already

  caused.

  (B) Closing existing nuclear power plants would require

  greatly increased reliance on coal-and oil-burning

  power plants.

  (C) The harm that has resulted from operation of

  existing coal and oil-burning power plants has

  been significant.

  (D) The harm that a nuclear power plant is likely to

  cause as it continues to operate can be reliably

  predicted from the past history of nuclear power

  plants.

  (E) The only harm that has resulted from operation of

  existing coal and oil-burning power plants has

  resulted from the pollution generated by these

  plants.

  (F) Closing existing nuclear power plants would require

  increased reliance on coal-and oil-burning power

  plants.

  11. Sleep deprivation is a known cause of workplace

  error, and many physicians frequently go without

  sleep for periods of 24 hours or more. However, few

  of these physicians have, in the course of a routine

  examination by a peer, been diagnosed with sleep

  deprivation. So there is little cause for concern that

  habitual sleep deprivation will cause widespread

  physician error.

  The answer to which of the following questions

  would be most helpful in evaluating the argument?

  (A)Do physicians who have been diagnosed with

  sleep disorders also show signs of other ills not

  related to sleep deprivation?

  (B)Is the ability to recognize the symptoms of sleep

  deprivation in others significantly impaired by

  habitual sleep deprivation?

  (C)Do factors other than habitual sleep deprivation

  ever lead to errors in the workplace on the part

  of physicians?

  (D)Of people who have recently been treated by

  physicians, what percentage believe that many

  physicians have occasionally suffered from sleep

  deprivation?

  (E)Is the incidence of sleep deprivation higher

  among physicians than it is among other health

  care workers?

  12. The organizers of tomorrow’s outdoor concert

  announced that it will go on tomorrow on schedule

  unless bad weather is forecast or too few advance

  tickets are sold. If the concert is canceled, refunds

  will be made to ticket holders. Since some ticket

  holders have already been issued refunds even though

  more than enough advance tickets were sold, it must

  be the case that bad weather is forecast.

  Which of the following is an error of reasoning

  contained in the argument?

  (A) It proceeds as if a condition, which by itself is

  enough to guarantee a certain result, is the only

  condition under which that result would occur.

  (B) It bases a conclusion that is known to require

  two conditions on evidence that bears on only

  one of those conditions.

  (C) It explains one event as being caused by another

  event, even though both events must actually

  have been caused by some third, unidentified

  event.

  (D) It treats evidence for the absence of one condition

  under which a circumstance would occur

  as conclusive evidence that that circumstance

  will not occur.

  (E) Evidence given to support the conclusion actually

  undermines it.

  13. When six out of ten people who had eaten the egg

  salad at an office party became ill shortly after-

  ward, the leftover egg salad was tested. Testing

  failed to confirm the presence of any harmful

  bacteria in the egg salad. It follows that the egg

  salad was not responsible for the illness of any of

  the people who ate it.

  Which of the following is an error in the reasoning

  of the argument above?

  (A) Treating the cause of a sequence of events as if

  it were the result of that sequence of events

  (B) Rejecting a possible explanation without

  suggesting an alternative explanation

  (C) Failing to consider the possibility that those

  who did not become ill shortly after eating

  the egg salad became ill later

  (D) Treating a lack of proof that something is the

  case as constituting sufficient proof that it is

  not the case

  (E) Overlooking the possibility that some people

  are more susceptible to harmful bacteria

  than are other people

  14. Which of the following most logically completes the

  argument below?

  In recent years, the proportion of car buyers who buy

  new cars rather than used cars has declined.Some

  consumers have attributed this change to an increase

  in new-car prices.As evidence of the price increase,

  they cite figures that show that, even adjusting for

  inflation, the price that the buyer of a new car pays,

  on average, is far higher now than a few years ago.

  This evidence is unpersuasive, however, because___

  (A)the value of a car that is bought new declines

  much more rapidly than does the value of a

  car that is bought used

  (B)after someone has bought a car, it might be

  several years before that person next buys

  a car

  (C)a decline in the proportion of car buyers who

  buy new cars must necessarily mean that the

  proportion who buy used cars has increased

  (D)the relative increase in used-car sales might be

  explained by the decisions of only a small

  proportion of all car buyers

  (E)the change in the average price paid for a new

  car could result solely from more people’s

  rejecting inexpensive new cars in favor of used

  cars

  15. Which of the following most logically completes the

  argument below?

  Alone among living species, human beings experience

  adolescence, a period of accelerated physical growth

  prior to full maturity. Whether other hominid species,

  which are now all extinct and are known only through

  the fossil record, went through adolescence cannot be

  known, since _____

  (A) the minimum acceleration in physical growth

  that would indicate adolescence might differ

  according to species

  (B) the fossil record, though steadily expanding, will

  always remain incomplete

  (C) detecting the adolescent growth spurt requires

  measurements on the same individual at different

  ages

  (D) complete skeletons of extinct hominids are

  extremely rare

  (E) human beings might be the first species to benefit

  from the survival advantages, if any, conferred

  by adolescence

  16. Medical personnel who served in heavy combat in

  a recent war-even those who escaped physical

  injury-now have lower incomes and higher divorce

  rates, and score lower on psychological profiles measur-

  ing general happiness, than medical personnel who

  served in less stressful settings during that war. This

  evidence demonstrates that exposure to heavy-combat

  situations produces serious adverse effects, even

  among those who suffered no physical harm.

  Which of the following, if true, most strengthens

  the conclusion drawn above?

  (A) The medical personnel who served in heavy

  combat had completed significantly less

  schooling prior to military service than had

  other medical personnel.

  (B) The medical personnel who served in heavy

  combat tended to be younger at the time of

  their entrysintosmilitary service than were

  other medical personnel.

  (C) Parents of medical personnel who served in heavy

  combat show no significant difference in

  incomes, divorce rates, or general happiness

  from parents of other medical personnel.

  (D) Income levels, divorce rates, and levels of general

  happiness are the same for the medical

  personnel who served in heavy combat as

  they are for construction workers.

  (E) Medical personnel who served in heavy

  combat in an earlier war show no significant

  difference in incomes, divorce rates, or

  general happiness from other medical

  personnel who served in that war.

  17. Jan: People should not go to the new exhibition of

  Thornton’s paintings. Thornton will be given a

  portion of the admission proceeds and Thornton,

  a violent sociopath, should not be supported.

  Kim: Your recommendation is inconsistent with your

  actions, because you read poems by poets who

  also were violent sociopaths.

  Which of the following, if true, provides the strongest

  basis for Jan to counter Kim’s argument?

  (A) Thornton’s portion of the exhibition’s proceeds

  are being donated to a cause deemed worthy

  by Thornton.

  (B) It is quite difficult, if not impossible, for Jan to

  discover the behavioral tendencies of the artists

  Jan reads.

  (C) Kim does not use products made by companies

  whose hiring practices Kim finds abhorrent

  (D) The poets derived no benefit from Jan’s reading

  their poems.

  (E) The poets’violent behavior is better known to

  the public than is Thornton’s violent behavior.

  18. It is illogical to infer a second and different effect from a cause whi

  ch is known only by one particular effect. This is incorrect because the inf

  erred effect must necessarily be produced by some different characteristic o

  f the cause than is the observed effect, which already serves entirely to de

  scribe the cause.

  Which one of the following arguments makes the same logical error as the one

  described by the author in the passage?

  (A) An anonymous donor gave a thousand dollars

  to our historical society. I would guess that

  that individual also volunteers at the

  children’s hospital.

  (B) The radioactive material caused a genetic mutation,

  which, in turn, caused the birth defect. Therefore, the

  radioactive material caused the birth defect.

  (C) The city orchestra received more funds from the local

  government this year than ever before. Clearly this

  administration is more civic-minded than

  previous ones.

  (E) If I heat water, which is a liquid, it evaporates. If I

  heat hundreds of other liquids like water, they

  evaporate. Therefore, if I heat any liquid like water,

  it will evaporate.

  19. Economist: Any country that is economically

  efficient will generate wealth. Such a

  country will remain politically stable

  only if that wealth is distributed equitably.

  The equitable distribution of wealth puts

  an end to risk taking, the indispensable

  precondition of economic efficiency.

  Which of the following conclusions can be properly

  drawn an the basis of the statements above

  (A) No country can indefinitely remain both

  economically efficient and politically stable.

  (B) No country can indefinitely remain both

  politically unstable and wealthy.

  (C) Economic efficiency is the indispensable

  precondition for the generation of wealth in

  a country.

  (D) Any country in which wealth is distributed

  equitably will indefinitely remain politically

  stable.

  (E) Growing economic efficiency encourages risk

  taking, which in turn leads to further growth

  in economic efficiency.

  20. In the past ten years, there have been several

  improvements in mountain-climbing equipment.

  These improvements have made the sport both safer

  and more enjoyable for experienced climbers. Despite

  these improvements, however, the rate of mountain-

  climbing injuries has double in the past ten years.

  If all of the statements above are true, which of the

  following, if true, best reconciles their apparent

  discrepancy?

  (A) Many climbers, lulledsintosa false sense of security, use the new equipm

  ent to attempt climbing reats of which they are not capable.

  (B) Some mountain-climbing injuries are caused by

  unforeseeable weather conditions.

  (C)Mountain climbing, although a dangerous sport, does

  not normally result in injury to the experienced climber

  (D) In the past ten years there have been improvements in

  mountain-climbing techniques as well as in mountain-

  climbing equipment.

  (E) Although the rate of mountain-climbing injuries has

  increased, the rate of mountain-climbing deaths has

  not changed.

  --

  I would fly you to the moon and back

  If you’ll be if you’ll be my baby

  Got a ticket for a worldswhereswe belong

  So would you be my baby