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标题: GMAT 逻辑分析题 (8) [打印本页]

作者: sdcar2010 时间: 2010-11-16 11:00
标题: GMAT 逻辑分析题 (8)
If there is any fierce competition in the Asian Games in Guangzhou, the attending audience will be treated to a mesmerizing and memorable moment. But there will not be a mesmerizing and memorable moment unless there are diehard sports fans in the audience. To be a diehard sports fan, one must understand the spirit of sports.

If all the statements above are true, which one of the following statements must also be true?

A) If there are no diehard sports fans in the audience, then there will be no fierce competition in the Asian Games in Guangzhou.

B) No people who understand the spirit of sports will be in the audience if the audience will not be treated to a mesmerizing and memorable moment.

C) If there will be people in the audience who understand the spirit of sports, then at least one competition in the Asian Games in Guangzhou will be fierce.

D) The audience will be treated to a mesmerizing and memorable moment unless there are people in the audience who do not understand the spirit of sports.

E) If there are diehard sports fans in the audience, then there will be fierce competition in the Asian Games in Guangzhou.

作者: kevin0214 时间: 2010-11-16 12:14
A
推理链：any fierce competition →mesmerizing and memorable moment→diehard sports fans →understand the spirit of sports

作者: sdcar2010 时间: 2010-11-16 12:29
Yes, we got a winner!

作者: holyxie 时间: 2011-7-1 23:46
想请问下为什么E不对？

作者: sdcar2010 时间: 2011-7-2 09:29
This is a formal logic problem. In formal logic, recognition of trigger is very important. Trigger is the sufficient condition in an If ..., then ... statement.

From the stimulus:
But there will not be a mesmerizing and memorable moment unless there are diehard sports fans in the audience.
Or in If/then form:
If there are NOT diehard sports fans in the audience, then there will not be a mesmerizing and memorable moment.

There is not statement in the stimulus with "diehard sports fans" as the trigger (sufficient condition). Therefore, E) is wrong.

作者: holyxie 时间: 2011-7-2 22:52
知道了谢谢

作者: alex168 时间: 2011-7-3 03:57
could anyone pls explain why C is not right?

作者: sdcar2010 时间: 2011-7-3 11:02

could anyone pls explain why C is not right?

-- by 会员 alex168 (2011/7/3 3:57:58)

The reason is the same: no trigger for C).

The last sentence in the stimulus:
To be a diehard sports fan, one must understand the spirit of sports.
Or: If one is a diehard sports fan, then one understands the spirit of sports.
Note: "one understands the spirit of sports" is not a sufficient condition (trigger).
C) If there will be people in the audience who understand the spirit of sports, then at least one competition in the Asian Games in Guangzhou will be fierce.

C) needs "one understands the spirit of sports" to be a trigger. However, no trigger can be found in the stimulus.

作者: sanlingjie 时间: 2011-7-3 12:15
楼主~~~~~又是我~~~~~~我想请教你一提OG上的CR，我看你之前帮别人解答过答案C，可是我对答案D，不明白，为什么OG解释是support，我以为是无关。因为D完全没有提到19世纪，只是进行了现在人平均年龄的对比。你帮我看看吧。下面是原文和选项

OG12逻辑第1题

1. “Life expectancy” is the average age at death of the entire live-born population.
In the middle of the nineteenth century, life expectancy in North America was 40
years, whereas now it is nearly 80 years. Thus, in those days, people must have
been considered old at an age that we now consider the prime of life.

Which of the following, if true, undermines the argument above?

(A) In the middle of the nineteenth century, the population of North America was
significantly smaller than it is today.

(B) Most of the gains in life expectancy in the last 150 years have come from
reductions in the number of infants who die in their first year of life.

(C) Many of the people who live to an advanced age today do so only because of
medical technology that was unknown in the nineteenth century.

(D) The proportion of people who die in their seventies is significantly smaller
today than is the proportion of people who die in their eighties.

(E) More people in the middle of the nineteenth century engaged regularly in
vigorous physical activity than do so today.

作者: sanlingjie 时间: 2011-7-3 12:17
额。。不好意思。。D不是现在平均年龄的对比，是现在人70和80岁人数的对比。。。但这也和结论无关啊。。结论涉及19世纪，但这个不涉及的~~~~~~~~~·真的不明白为啥是support

作者: CatCandy 时间: 2011-8-5 16:55
My logic：fierce competition导致 mesmerizing and memorable moment 只要diehard sports fans 一定有spirit

我觉得是这个逻辑，但是用这个逻辑来看哪个选项都不对，哪个地方那个出错了呢？求助啊～～～

作者: sdcar2010 时间: 2011-8-5 20:48
If there is any fierce competition in the Asian Games in Guangzhou, the attending audience will be treated to a mesmerizing and memorable moment. But there will not be a mesmerizing and memorable moment unless there are diehard sports fans in the audience. To be a diehard sports fan, one must understand the spirit of sports.

Fierce competition --> m&m moment
m&m moment --> diehard fans
diehard fans --> understand the spirit of sports.

Inference:
1) Fierce competition --> diehard fans
2) Fierce competition --> understand spirit of sports
3) m&m moment --> understand the spirit of sports

作者: jeffxu 时间: 2011-8-9 16:16
Scar2010,

Thank you very much for all the examples and the series of posts about CR.

I don't agree with you on this question.
Fierce competition --> m&m moment
m&m moment --> diehard fans
diehard fans --> understand the spirit of sports.

My understanding is that, fierce competition is a kind of objective phenominon but only people who're diehard fans can recognize it and enjoy it. To become a diehard fans you've to understand the sprit of sports.

So two parallel premises:
1, fierce competition
2, diehard fans
together treat the audience with m&m.

I agree that If there are NOT diehard sports fans in the audience, then there will not be a mesmerizing and memorable moment. But I disagree that "If there are no diehard sports fans in the audience, then there will be no fierce competition in the Asian Games in Guangzhou."

作者: sdcar2010 时间: 2011-8-9 22:04
Fierce competition --> m&m moment
m&m moment --> diehard fans

If you acknowledge the above premises, then their contrapositives are correct:
No diehard fans --> No m&m moment
No m&m moment --> No fierce competition

Therefore, No diehard fans --> No fierce competition

For formal logic questions in CR, do not add your own objective/subjective opinions to the logic chains in the passage. Remember, we are analyzing the author's logic reasonings here, not yours. ONLY focus on the logic statements in the passage and go from there.

作者: AlohaDJ 时间: 2011-8-10 01:37
Thks NN for the explanations.

My summary from this question:
1. A unless B: A ->B (after UNLESS is a necessary condition)
2. To / in order to represents the if-part in if-then statements.

作者: sdcar2010 时间: 2011-8-10 02:35

Thks NN for the explanations.

My summary from this question:
1. A unless B: A ->B (after UNLESS is a necessary condition)
2. To / in order to represents the if-part in if-then statements.

-- by 会员 AlohaDJ (2011/8/10 1:37:05)

A unless B: Not A --> B (You have to negate the claim in A to make it a sufficient condition).

Not A unless B: A --> B

作者: AlohaDJ 时间: 2011-8-10 14:00

Thks NN for the explanations.

My summary from this question:
1. A unless B: A ->B (after UNLESS is a necessary condition)
2. To / in order to represents the if-part in if-then statements.

-- by 会员 AlohaDJ (2011/8/10 1:37:05)

A unless B: Not A --> B (You have to negate the claim in A to make it a sufficient condition).

Not A unless B: A --> B

-- by 会员 sdcar2010 (2011/8/10 2:35:13)

oh..YES!! Negation of A is indispensable here!
THKS NN for pointing it out!!

作者: jeffxu 时间: 2011-8-10 14:47
Thank you sdcar2010.I was also wondering that I may take some of my own opinions into account for this question.

Fierce competition --> m&m moment
m&m moment --> diehard fans

If you acknowledge the above premises, then their contrapositives are correct:
No diehard fans --> No m&m moment
No m&m moment --> No fierce competition

Therefore, No diehard fans --> No fierce competition

For formal logic questions in CR, do not add your own objective/subjective opinions to the logic chains in the passage. Remember, we are analyzing the author's logic reasonings here, not yours. ONLY focus on the logic statements in the passage and go from there.

-- by 会员 sdcar2010 (2011/8/9 22:04:06)

作者: corrine90 时间: 2011-8-20 09:52
sdcar, I have a question about the trigger. Is it something that appears in the stimulus? I saw you say sufficient conditon, so I think the trigger must appear as it does in the stimulus, am I right?

作者: sdcar2010 时间: 2011-8-20 10:27

sdcar, I have a question about the trigger. Is it something that appears in the stimulus? I saw you say sufficient conditon, so I think the trigger must appear as it does in the stimulus, am I right?

-- by 会员 corrine90 (2011/8/20 9:52:35)

That's right. The trigger is the sufficient condition in a logic statement. Because without the trigger, you won't logically reach the necessary condition.

作者: kathyrn 时间: 2013-11-18 22:53
谢谢楼主

作者: livebelieve 时间: 2016-11-5 10:26

我发现，一般有三句话的句子，只要把前两句的关键词抽出来就好，第三句讲了啥根本没所谓。。。。

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