For years the beautiful Renaissance buildings in Palitito

[andrew1]

For years the beautiful Renaissance buildings in Palitito have been damaged by exhaust from many tour buses that come to the city. There has been little parking space, so most buses have idled at the curb during each stop on their tour, and idling produces as much exhaust as driving. The city has now provided parking that accomodates a third of the tour buses, so damage to Palitito's buildings from the buses' exhaust will diminish significantly.

Which of the follwing, if true, most strongly supports the argument?

A) The exhaust from Palitito's few automobiles is not a significant threat to Palitito's buildings.

B) Palitito's Renaissance buildings are not threatened by pollution other than engine exhaust.

C) Tour buses typically spend less than one-quarter of the time they are in Palitito transporting passengers from one site to another.

D) Most tourists come to Palitito by tour bus than by any other single means of transportation.

E) Some of the tour buses that are unable to find parking drive around Palitito while their passengers are visting a site.

Answer: C

A and B seem to be to be similar assumptions underlying the argument. I'm not exactly sure how answer choice C affects the argument - if they are spending less than 1/4 the time driving, then 3/4 they are parked or idling, and then . . .
D is out of the argument's scope.
For E, if some of the tour buses that cannot find parking drive then will they now be parked, or would they not have caused damage to the Renaissance buildings in the first place?

Thanks!

[H]

A lot of people say that C is correct because:
If the tour buses only spend about 1/4 of the time on driving from 1 site to another, then it means that about 3/4 of the time, the buses will idle next to the building.
With a new parking lot, approximately 3/4 of the damage will go away because the buses will idle in the parking lot instead.

However, I thought that B was correct.
Here is my logic:
If engine exhaust is the ONLY thing that can damage the building, then the new parking lot will help a lot because even the bus only idles for 0.00001 sec next to the building, the parking lot virtually removes the ONLY possible pollutant source.

I want to see whether there are some keywords that I miss...or for this type of question, what the GMAC's logic is..

Thanks.

[H]

In fact, this question appears in the diagnostic test in OG11(yellow) as well.
The question # is 32.
But I still don't understand why B is irrelevant.
With B, the argument is stronger because the engine exhaust is the ONLY pollution that damages the build, and the new parking will reduce the chance/time that tour buses idle at the curb next to the building.
Anything wrong with my logic?
Thanks in advance.

[RonPurewal]

nope, answer (b) is completely irrelevant to the argument.

notice the essential modifier in the CONCLUSION of the argument, which states that
damage to Palitito's buildings from the buses' exhaust will diminish significantly.

you can't get rid of that modifier; it's an integral part of the conclusion. therefore, the conclusion only deals with reducing the damage due to bus exhaust. damage from other sources of pollution is simply not pertinent.

this is an EXTREMELY common type of wrong answer: try to deflect the argument onto a topic that's simply not part of it.

here's another example:
let's say a CR passage's conclusion states that "taking drug X is an effective way to lose weight", and challenges you to WEAKEN that conclusion.
and let's say answer choice (a) states that "exercise generally causes faster weight loss than do diet drugs."
as tempting as this choice is, it's wrong, because it does NOTHING to undermine the connection between drug x and weight loss. even if exercise is conclusively better than drug x, that still doesn't do anything to show that drug x is ineffective.

same sort of thing here. just as the aforementioned example is only concerned with the connection between drug x and weight loss, this passage is only concerned with the connection between bus exhaust and building damage. whether the buildings are also damaged by other sources of pollution is immaterial.

[H]

Thanks a lot Ron!

[RonPurewal]

Thanks a lot Ron!

all good.

[soundok]

But I still can not figure out why C is corret?

Is choice C is a new information to support the conclusion?

If it is not a new info, what is the relationship between " idle at the curb during each stop to produce exhaust" and "spend less than 1/4 of the time..."?

[RonPurewal]

But I still can not figure out why C is corret?

Is choice C is a new information to support the conclusion?

If it is not a new info, what is the relationship between " idle at the curb during each stop to produce exhaust" and "spend less than 1/4 of the time..."?

choice (c) provides the new information that the buses spend 3/4 of the total time - i.e., all the time that they don't actually spend transporting passengers - either parking or idling. since, according to the passage, most buses idle rather than park, this means that most buses spend 3/4 of their total time idling in front of historic buildings.

this is strong new evidence that the idling is A Big Problem, since it comprises the majority of the time spent in the city by these buses.

[philanderer.lover]

Ron,

Please explain why E is wrong?

Regards,
Philand

[vivekcall81]

i also felt that E is correct but, read carefully, the argument says that even if parking is not avialable the buses idle and they produce same exhaust during running or idling. we have to a find a statement that makes argument stronger. but E repeats the premise in other way.
if i can proove that idling time is more than running time, i can say that the buses are producing more exhuast and this exhaust causes pollution.
in this way C i seems correct.

[philanderer.lover]

i also felt that E is correct but, read carefully, the argument says that even if parking is not avialable the buses idle and they produce same exhaust during running or idling. we have to a find a statement that makes argument stronger. but E repeats the premise in other way.
if i can proove that idling time is more than running time, i can say that the buses are producing more exhuast and this exhaust causes pollution.
in this way C i seems correct.

Thankyou for the explanation.

I am sorry to say but I still dont understand.....

E says this
Some of the tour buses that are unable to find parking drive around Palitito while their passengers are visting a site.

it says that by creating more parking spaces pollution will reduce by exhaust.....so what is the difference bet C and E

[RonPurewal]

E) Some of the tour buses that are unable to find parking drive around Palitito while their passengers are visting a site.

this statement doesn't help the argument at all, since we already know that, if the buses can't find parking, they either idle at the curb or drive around. since there is no difference in the amount of exhaust between idling and driving around, this statement doesn't have any effect.

in other words, here's how you should think about it: the issue in choice (e) is not parking vs. driving around. since this choice is talking about buses that can't find parking, the issue is actually driving around vs. idling[/i] -- which, as stated in the passage, works out identically either way in terms of pollution.

--

furthermore, note that the statement just says "some buses". generally, "some" is used to indicate a relatively small fraction of a group -- so, even if this statement were about something that had a statistical effect upon pollution (which it doesn't), it would still be a small effect.

(in general, here's the way these terms are usually used. THESE ARE NOT FORMAL STATISTICS AND ARE NOT MEANT TO BE TAKEN LITERALLY AT FACE VALUE; rather, they are simply indications of the way the terms are normally used in arguments the english language.
"some" --> intuitively, 1/4 or less of the total
"many" --> intuitively, between 1/4 and 1/2 of the total
"most" --> intuitively, between 1/2 and 3/4 of the total
"almost all" --> intuitively, more than 3/4 of the total)

also note that THESE INTERPRETATIONS DO NOT APPLY TO QUANTITATIVE PROBLEMS!
for instance, if i say "some of the numbers in set S are prime", then it's totally possible that, say, 99 out of 100 numbers in S are prime.
in normal (non-quantitative) english, however, this is not the way in which these words are used.

by contrast, choice (c) has a huge statistical effect -- the buses spend less than 25% of the time actually in transit, meaning that they spend more than 75% of the time idling or driving around! therefore, the parking issue is a huge issue. (if the buses spent almost all their time in transit, then the argument would be substantially weakened, as they wouldn't park for long enough to reduce pollution.)

[brparajuli]

Sorry to open up the new thread, but I am just trying to understand the GMAC's logic here.

Since those buses that drive around right now will go to the parking lot, does not that reduce the exhaust?

[thanghnvn]

Thank you Ron.
The problem with most student is that they can not get the right answer in a good time.
Dong CR is prephrasing assumption and the correct answer before going to answer choices.

Ron, Can you detail the process of prephrasing assumptions and the correct answer for this question ?

I think prephrasing is the key to success on CR but most of the discussion here is not about prephrasing.

Ron, you are native speaker and it is possible the there is some step which the native do unconciously. we, the non native, want you to detail your process of thought for a question, specifically for this question.

what do you prephrase before going to answer choices ? . pls, detail this step. Thank you

[RonPurewal]

Sorry to open up the new thread, but I am just trying to understand the GMAC's logic here.

Since those buses that drive around right now will go to the parking lot, does not that reduce the exhaust?

that is exactly how this answer choice works. for the precise reason you've stated here, it strengthens the argument.