Driving the steep road to the mountain-top Inca ruins of Machu Picchu

You are wrong and forgiven
jus kidding....coming to your argument,
"since the presence..." is not the conclusion,the conclusion is the second part which says "cable cars are bad for Machu picchu". disagree? read the sentence you have written above as conclusion. what is the "this"?
that is the conclusion and the first part is the premise. not convinced? ask yourself what is a premise? and what is a conclusion?(since obviously u know these terms it is easy to define it). A premise supports the conclusion and a conclusion is something that the argument says is true because of the premise. now break down the sentence in question. "since the presence.." is saying the reason why "cable cars are bad for machu picchu". Now what is the conclusion?
secondly,you almost never weaken the premise. It is the conclusion that you should attack, remember in every argument gmat will try invalidate the conclusion(main conclusion or sub conclusion) because an argument will have only one conclusion but many premises, it is easier to contradict that conclusion than to contradict several premises.

Hope this helps!!

(E)

The passage implies cars->more tourists->more damage. If (E) is true, then cable cars may actually result in less damage.

Correct me. E is answering why the author thinks tour buses WILL destroy the site. Are you answering why cable car will NOT destroy the site. I don't think so. Furthermore the arg is dependent on the number of tourists visiting the place. Reread the stimulus - "cable car .... access much ..... increase in tourism... tends to accelerate the deterioration of a site". How can E be the answer?

E.g If the defense attorney is alluding that X is better killer than Y - does that precludes Y from assisting in the crime? Same here. Hence choice E does not hold water. It has to answer the question "why" cable car will NOT destroy the site. And premise should verify that cable cars are technologically advanced. I don't see the support.

Hi Guys ,

Pls forgive me if I am wrong But

Concl :

since the presence of large numbers of tourists tends to accelerate the
deterioration of a site so this is causing the harm . The impact of the Cable car or Tourist Bus is immaterial isin't it.

TO weaken the premise :
We need to show How the reduced people will improve the site beauty or reduce deterioration
Or
Since Machu Pichu is already crowded ... no matter what is done like cable cars or buses , the deterioration will continue immaterial to the transportation methods

So I think C is the answer But I am open to a debate since I may be wrong.

glad to help!!
perhaps one day you might return the favor when i am stuck!!
till then i'll be content if you give me a kudos by pressing +1 kudos under my display name.

Hello, Ujaswin. You put your finger on the exact conclusion of the argument, but your own conclusion, which I have highlighted in red above, deviated from the correct line of logic. You are only supposing or assuming that the cable car will cause such harm. Maybe it will not. We simply do not know one way or the other, but the argument falls into a logical trouble zone when it asserts, well, the exact conclusion you outlined above: installation of the cable car is certain to result in harm to the ruins.

In the interest of helping the community, I will offer my thoughts on each of the answers below.


Since we are looking to call into question or weaken the argument, we have to be careful to stick to the exact logic of the argument. The only certainty given in the argument is that

the Peruvian government is installing a cable car.

The conclusion that follows just after is speculation:

[installation of a cable car will] result in a large increase in tourism.

This could be true, but we cannot be certain of this influx of tourists. Thus, the premise that follows is already on shaky ground:

the presence of large numbers of tourists tends to accelerate the deterioration of a site

Again, we cannot be certain that tourists will suddenly turn up in droves, but I also want to point out how tends to in the middle of the premise also does not lead to a certainty. I can say that during the monsoon season in a certain area, it tends to rain quite frequently, but is not the same as saying that it will or must rain. That is, I cannot wake up in such a place and predict that it will rain with 100 percent certainty even if it is probable. And finally, we get the conclusion:

installation of the cable car is certain to result in harm to the ruins

We already know by now that this conclusion is premature, but what do the answer choices have in store for us?


Analysis: What does the original resident population of Incas have to do with the argument at all? The word original is troubling me here. Are we to understand that this tag refers to the Incas of some pre-Columbian time? Are we to then extend our reasoning that if such an original population did not destroy Machu Picchu, then neither will a smaller group of people? For one thing, the indigenous peoples were not skirting up the mountain in cable cars; for another, as a test-taking note, whenever you find yourself really stretching to justify an answer in CR, it is almost always going to prove incorrect. There is a linear line of logic to follow, and this one steers off-course pretty fast. There is nothing to put a dent in the argument that installing the cable car will cause damage to the ruins. That is, the argument could remain intact. Red light.


Analysis: If anything, this answer makes it sound as if the outcome were more definite. The use of potentially damaging heavy machinery at the site sounds pretty ominous. Although, once again, the outcome is not a certainty, the argument is not being dismantled at all by this consideration. Red light.


Analysis: Great, but this could play right into the logic of the argument. Maybe more people will visit once the cable car makes the site more accessible. On the other hand, maybe more people will not visit, but the installation of the cable car could still cause harm to the site. This information has no bearing on the argument one way or the other. Red light.


Analysis: This is a tempting distraction, since a different factor, natural weathering, is said to continue to be a more significant cause of the deterioration of the site. In other words, tourists are apparently not the primary destructive force. The problem is that the argument does not rank causes of deterioration. It is based instead on the installation of a cable car at the site, an action that will drive in more tourists, who, in turn, will accelerate the deterioration of Machu Picchu. The argument is not affected if weather proves more destructive than foot traffic. Red light.


Analysis: Now we are swapping out one mode of transportation with another, but it is the tour buses that at present do significant damage to the site. In other words, we know or can be certain only that buses are damaging the site, not that the cable car will be when it replaces the buses. Such a conclusion is pure speculation, weakening the certain part of the conclusion. Green light.

I had a lot of fun with this one. I, too, would like to know the source of the question, since whatever source it comes from does mimic an official question quite well, a feat that many third-party sources do not achieve.

If anyone has any further questions, feel free to post a response. Good luck with your studies.

- Andrew

I think we have to answer - why installation of "cable cars" will NOT result in damage. E is strengthening the argument not weakening.

E. Because option E tells that the car is replacing the bus. As the car replacing bus, so the arguement is faulty.

I was stuck between A & E. Ended up choosing A because although option E is offsetting the damage to a little extent by replacing buses with cable cars it doesn't seriously weaken the argument. The argument requires us to weaken "installation of the cable car is certain to result in harm to the ruins." Option E just reduces this certainty.

Option A on the other hand weakens this conclusion, if we draw parallels between the human population which was present earlier and the no.of the tourists.

E - weakens by supporting the conclusion.

tip - for weakening questions look for logical gap. don't destroy the conclusion.

gmat1220 what you are asking for is a "perfect answer" to the question(something that says cable is eco friendly or something). wat u are saying about X and Y is indeed true. however in the absence of an answer that completely precludes cable cars,we shud choose one that is closest. and E does that. by saying cable cars are better than buses, we can saying cable cars are a better choice for manchu picchu. Maybe not the best, but definitely a better choice. So the conclusion is weakened(though only slightly).
Hope this helps!!
by the way ppl, wat is the source of this CR?

Superb Explanation !!!!!


I have to accept I am wrong !!

Definition of premise and Concl is real good !

U rock

Option E.
If the cable cars will replace something already more damaging to the MP site,then the argument that cable cars will lead to deterioration is weakened.

Posted from my mobile device

Explanation for choice D

Type: Weaken

Conclusion: installation of the cable => harm to the ruins

Assumption: installation of the cable is more harmful than current transportation used to get to the ruin.

Weaken the assumption: thr traditional way to get to the ruin is more harmful to the hostorical site

I think key to answer this question "accelerate the deterioration of a site,"

What if X slow downs the deterioration of a site
Assumption :- X will not slow down the deterioration of a site
E clearly says the same.

Another way to see the problem is
X will lead to Y
Presenting another reason z will lead to Y , will not weaken the X as a reason.
in such cases we have check even X will be implemented , will it affect chances of Y

It appears your explanation is actually suited to E. Natural deterioration will happen anyway, so it is irrelevant to the argument about cable cars and more tourist traffic causing damage

But E does not says that buses do more damage than cable car
It only says that it does a significant damage
Are we supposed to assume it does more damage than cable car???
Experts plz help