gmat逻辑懂和不之间一剑封喉讲义

GMAT逻辑在懂与不懂之间一剑封喉1一个好消息＋一个坏消息：原文读懂就能做对很少能读懂2逻辑题的本质：有缺陷的argument34何为argument？摆事实（证），讲道理（论）。一段由论（观点，conclusion）和证（理由，

support）两个部分合在一起的完整文字，构成论证（argument）。其中，证可以不止一个，但论通常只有一个。论证的符号表示为：证

论缺陷（gap）与弥补（assumption）证1+证2论举例：黄大仙是理工男（证1）＋所有理工男都喜欢足球（证2）黄大仙喜欢足球（论）Reliability(信)vs.True

(真)加P37例1

证：

大仙是智障，他是GMAT老师，论：

智障也可以教GMAT

。例2

证：

大仙教GMAT教的那么好。论：他昨天参加GMAT考试一定700+。缺陷（gap）与弥补（assumption）缺陷（gap）与弥补（assumption）Reliability(信)vs.True

(真)加P37例1

证：

大仙是智障，他是GMAT老师，论：

智障也可以教GMAT

。假证通向可信论（尽管论也许是假）。例2

证：

大仙教GMAT教的那么好。论：他昨天参加GMAT考试一定700+。真证通向不可信论（尽管论也许是真）。缺陷（gap）与弥补（assumption）证1+证2论举例：黄大仙是理工男（证1）＋所有理工男都喜欢足球（证2）黄大仙喜欢足球（论）缺陷（gap）与弥补（assumption）证1

+

?

论举例：黄大仙是理工男（证1）GAP黄大仙喜欢足球（论）缺陷（gap）与弥补（assumption）证2+?论举例：所有理工男都喜欢足球（证2）GAP黄大仙喜欢足球（论）缺陷（gap）与弥补（assumption）Assumption就是gap的弥补，那个没被说出来的证。加强题是对gap进行缩小或填补；削弱题是对gap进行强调或攻击。缺陷（gap）与弥补（assumption）解释题是对gap进行缩小；Assumption题是找出gap的弥补；评价题是指出gap放大或缩小所依赖的变量；归纳题是找出原文（证）选项（论）之间gap最小的选项；填空题是解释题或归纳题的变体。缺陷（gap）与弥补（assumption）CR题的原文往往不止一个gap。我们学校理工男都很喜欢看足球比赛，黄大仙数学很好，（证）黄大仙喜欢踢足球（论）缺陷（gap）与弥补（assumption）CR题的原文往往不止一个gap。我们学校理工男都很喜欢看足球比赛，且所有时代所有地方的理工男都一样，黄大仙数学很好，他是男性，且一般数学好的男人就定义为理工男，喜欢看足球的人都喜欢踢足球（证）因此，黄大仙喜欢踢足球（论）15所以读懂的关键找到这些GAP的位置16三大技巧识类别识偏轨识好坏17技巧1

识种类什么是类？就是给原文讨论对象加的标签，或划分的种群。常见特征：定语。识类别要求我们找到原文或选项在讨论时对象种类的变化。18模型我们注意到某种X事物，在其所处的Y类别中有Z行为，因此，所有的

X事物都有Z的相似特征。例题Automobile

Dealer's

Advertisement：

The

HighwayTraffic

SafetyInstitute

reports

that

the

PZ

1000

has

the

fewest

injuries

per

accident

ofany

car

in

its

class.

This

shows

that

the

PZ

1000

is

one

of

the

safest

carsavailable

today.

Which

of

the

following,

if

true,

most

seriouslyweakens

the

argument

in

the

advertisement?A

The

Highway

Traffic

Safety

Institute

report

listed

many

cars

in

otherclasses

that

had

more

injuries

per

accident

than

did

the

PZ

1000.B

In

recent

years

many

more

PZ

1000's

have

been

sold

than

have

anyother

kind

of

car

in

its

class.C

Cars

in

the

class

to

which

the

PZ

1000

belongs

are

more

likely

to

beinvolved

in

accidents

than

are

other

types

of

cars.D

The

difference

between

the

number

of

injuries

per

accident

for

the

PZ1000

and

that

for

other

cars

in

its

class

is

quite

pronounced.E

The

Highway

Traffic

Safety

Institute

issues

reports

only

once

a

year例题Smithtown

University's

fund-raisers

succeeded

in

getting

donations

from

80

percent

ofthe

potential

donors

they

contacted.

This

success

rate,

exceptionally

high

for

universityfund-raisers,

does

not

indicate

that

they

were

doing

a

good

job.

On

the

contrary,

sincethe

people

most

likely

to

donate

are

those

who

have

donated

in

the

past,

good

fund-raisers

constantly

try

less-likely

prospects

in

an

effort

to

expand

the

donor

base.

Thehigh

success

rate

shows

insufficient

canvassing

effort.

Which

of

the

following,

if

true,provides

more

support

for

the

argument?A

Smithtown

University's

fund-raisers

were

successful

in

their

contacts

with

potentialdonors

who

had

never

given

before

about

as

frequently

as

were

fund-raisers

for

otheruniversities

in

their

contacts

with

such

people.B

This

year

the

average

size

of

the

donations

to

Smithtown

University

from

newdonors

when

the

university's

fund-raisers

had

contacted

was

larger

than

the

averagesize

of

donations

from

donors

who

had

given

to

the

university

before.C

This

year

most

of

the

donations

that

came

to

Smithtown

University

from

people

whohad

previously

donated

to

it

were

made

without

the

university's

fund-raisers

havingmade

any

contact

with

the

donors.D

The

majority

of

the

donations

that

fund-raisers

succeeded

in

getting

for

SmithtownUniversity

this

year

were

from

donors

who

had

never

given

to

the

university

before.E

More

than

half

of

the

money

raised

by

Smithtown

University's

fund-raisers

camefrom

donors

who

had

never

previously

donated

to

the

university.21技巧2

识偏轨什么是偏轨？就是与本来的推理关系产生偏离。常见特征：因果，易混淆概念识偏轨要求我们识别出两事件之间貌似紧密实则松散的关系。22模型我们注意到某种X事物，可以与Y事物产生因果关系，因此，X’事物可以导致Y。例题Because

it

was

long

thought

that

few

people

would

watch

lengthy

televisedpolitical

messages,

most

televised

political

advertisements,

like

commercialadvertisements,

took

the

form

of

short

messages.

Last

year,however,

onecandidate

produced

a

half-hour-long

advertisement.

During

the

half

hour

theadvertisement

was

aired,

a

substantial

portion

of

the

viewing

public

tuned

intothe

advertisement.

Clearly,

then,

many

more

people

are

interested

in

watchinglengthy

televised

political

messages

than

was

previously

thought.

Which

ofthe

following

is

an

assumption

on

which

the

argument

depends?A

The

candidate's

ratings

improved

significantly

as

a

result

of

the

half-hour-long

political

advertisement.B

Political

advertisements

have

e

increasingly

influential

in

determining

voters'decisions

at

the

polls.C

Many

people

would

appreciate

the

opportunity

to e

better

acquainted

withpolitical

candidates'

views

on

current

political

issues.D

Most

people

who

are

interested

in

political

issues

watch

television

regularly.E

Most

of

the

viewers

who

tuned

in

to

the

candidate's

half-hour-longadvertisement

last

year

did

not

change

channels

after

the

first

few

minutes.例题Finding

of

a

survey

of

Systems

magazine

subscribers:

Thirty

percent

of

allmerchandise

orders

placed

by

subscribers

in

response

to

advertisements

in

themagazine

last

year

were

placed

by

subscribers

under

age

thirty-five.Finding

of

a

survey

of

advertisers

in

Systems

magazine:

Most

of

the

merchandise

ordersplaced

in

response

to

advertisements

in

Systems

last

year

were

placed

bypeople

under

age

thirty-five.

For

both

of

the

findings

to

be

accurate,

which

of

the

following

must

be

true?A

More

subscribers

to

Systems

who

have

never

ordered

merchandise

inresponse

to

advertisements

in

the

magazine

are

age

thirty-five

or

over

thanare

under

age

thirty-five.B

Among

subscribers

to

Systems,

the

proportion

who

are

under

age

thirty-fivewas

considerably

lower

last

year

than

it

isnow.C

Most

merchandise

orders

placed

in

response

to

advertisements

in

Systemslast

year

were

placed

by

Systems

subscribers

over

age

thirty-five.D

Last

year,

the

average

dollar

amount

of

merchandise

orders

placed

was

lessfor

subscribers

under

age

thirty-five

than

for

those

age

thirty-five

or

over.E

Last

year

many

people

who

placed

orders

for

merchandise

in

response

toadvertisements

in

Systems

were

not

subscribers

to

the

magazine.25技巧3识好坏什么是好坏？就是把自己代入到原文语境中，讲结论句看成好事坏事。再依次观察选项是在添油加醋，还是冷嘲热讽。例题Rail

Executive:

Five

years

age

we

discontinued

train

service

between

Lambertonand

its

suburbs

because

low

ridership

caused

total

fares

collected

to

besubstantially

lower

than

the

cost

of

operating

the

service

it

is

true

that

recentpopulation

growth

in

the

suburban

communities

suggests

increased

potentialridership,

nevertheless

since

most

of

the

newer

residents

own

automobiles,restoring

the

train

service

this

year

would

still

result

in

serious

deficits

Whichof

the

following

,if

true

casts

the

most

serious

doubt

on

the

rail

executive'sargument?A

once

train

service

along

a

given

route

has

been

discontinued

,there

aresubstantial

start-up

costs

associated

with

restoring

service

along

that

routeB

most

of

the

new

residents

of

Lamberton's

suburbs

do

not

need

to

travel

intoLamberton

regularly

for

shopping

or

recreationC

if

train

service

were

restored

this

with

increased

hours

of

service

there

wouldnot

be

an

increase

in

total

ridership

A

survey

conducted

last

year

showedthat

few

people

living

in

Lamberton

or

its

suburbs

support

increased

publicfunding

for

mass

transportationE

Recently

there

have

been

sharp

increases

in

parking

fees

in

Lamberton

and

inhighway

tolls

on

major

commuter

routes例题Printwell's

Ink

Jet

Division

manufactures

ink-jet

printers

and

the

ink

cartridges

theyuse.

Sales

of

its

ink-jet

printers

have

increased.

Monthly

revenues

from

those

sales,however,

have

not

increased,

because

competition

has

forced

Printwell

to

cut

theprices

of

its

printers.Unfortunately,

Printwell

has

been

unable

to

bring

downthecost

of

manufacturing

a

printer.Thus,

despite

the

increase

in

printer

sales,

the

InkJet

Division