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

Question

Driving the steep road to the mountain-top Inca ruins of Machu Picchu is potentially dangerous and hiking there is difficult. Now the Peruvian government is installing a cable car that will make access much easier, and hence result in a large increase in tourism. However, since the presence of large numbers of tourists tends to accelerate the deterioration of a site, installation of the cable car is certain to result in harm to the ruins.

Which of the following, if true, most seriously calls into question the argument?

Which of the following, if true, most seriously calls into question the argument?

(A) The daily number of tourists that are expected to take the cable car to Machu Piccu is smaller than the original resident population of Incas.

(B) The construction of the cable car terminal at Machu Picchu will require the use of potentially damaging heavy machinery at the site.

(C) Machu Picchu is already one of the most popular tourist sites in Peru.

(D) Natural weathering will continue to be a more significant cause of the deterioration of Machu Picchu than tourist traffic.

(E) The cable car will replace the tour buses whose large wheels and corrosive exhaust at present do significant damage to the site.

Divyadisha · Accepted Answer

To weaken the conclusion, we have to look for an option that states that installation of cable car will not result in deterioration.

A. The daily number of tourists that are expected to take the cable car to Machu Piccu is smaller than the original resident population of Incas.  We don't know how many tourists will cause the destruction of site.

B. The construction of the cable car terminal at Machu Picchu will require the use of potentially damaging heavy machinery at the site.  It supports the conclusion.

C. Machu Picchu is already one of the most popular tourist sites in Peru.  We are looking for an option that addresses damage to the site.

D. Natural weathering will continue to be a more significant cause of the deterioration of Machu Picchu than tourist traffic.  we want to knoe if cable car will cause more destruction.

E. The cable car will replace the tour buses whose large wheels and corrosive exhaust at present do significant damage to the site.  This means cable cars will infact be less damaging to the site. Correct answer

longhorn07 · Answer

(E)

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

gmat1220 · Answer

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

craky · Answer

Conclusion: Installation of the cable car is certain to result in harm to the ruins.
We are trying to weaken this conclusion.

E says: that the cable care will replace buses, which do damage now.

With their large wheels - cable car uses rails, so the road will not be damaged any more.
and corrosive exhaust - cable car runs on electricity, so no exhaust.

Furthermore, there won't be more tourists, only the means of transportation will be changed.

E weakens the argument and shows, that cable car will not result in harm to the ruins.

gmat1220 · Answer

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.

Steveewonder48 · Answer

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.

vinzycoolfire · Answer

You are wrong and forgiven :lol:

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!!

MHIKER · Answer

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

Hector1S · Answer

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.

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.

AndrewN · Answer

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:

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

agrasan · Answer

For folks who are confused between (D) and (E), note that our conclusion is "installation of the  cable car is certain to result in harm to the ruins " so we have to find an option that shows cable car might not result in harm to the ruins.

Now (D) says that natural weathering will continue to harm but it doesn't say anything that cable car will not do harm so our confidence in the conclusion remains unchanged whereas (E) directly hurts the conclusion by saying that cable car will do less damage because it will replace tires used currently.

Adit_ · Answer

Everybody seem to be making a conclusion that option E says that the cable car wont do damage. That is wrong!
Option E only says that one is doing significant damage at the moment that there is a chance to believe that the cable cars with no large wheels and corrosive exhaust COULD produce lesser damage.
There is also an argument where one could say with more tourists involved the damage caused by the cable cars will outweigh the damages by buses and that is true!
Option E is the BEST weakener because it gives us a chance to believe that cable cars MIGHT NOT accelerate the deterioration.

Option A is close IMO.
But the point here is that the number of tourists will most likely still be high whether its the daily tourists or residence people, the cable cars introduction is meant to increase number of people so the total numbers will still increase and accelerate the deterioration and doesnt give us enough reason to believe that it will not accelerate deterioration of site like option E does.

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

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

Prep Toolkit

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My Rewards