CR - Southern airways vs Air Dacentaria

[poonamchiK]

Traveler: Southern Airways has a far worse safety record than Air Dacentaria over the past few years, in terms of both the frequency of accidents and the severity of accidents. Therefore, although Air Dacentaria is slightly more expensive, I will choose it over Southern Airways for my flight from Pederton to Dacenta, since it is worth paying extra to have a safer flight.

Which of the following, if true, casts the most serious doubt on the traveler's argument?

(A) Air Dacentaria's flight from Pederton to Dacenta is nonstop, whereas Southern Airways' flight touches down in Gorinda on the way.

(B) Most Southern Airways flights, but not its flight from Pederton to Dacenta, use Sarmouth airport, which because of its mountainous location is one of the world's most dangerous.

(C) For its flights from Pederton to Dacenta, Southern Airways uses a different model of airplane, with a smaller capacity, than the model Air Dacentaria uses for its flights on the same route.

(D) Only in the last few years has the cost of flying from Pederton to Dacenta been more expensive on Air Dacentaria than on Southern Airways.

(E) Although the frequency of accidents is greater on Southern Airways, on both airlines the proportion of flights that have accidents is very small.

I am unable to understand wht E is trying to say. Thats wht I have chosen as my ans. Its wrong.
Second option was correct. But if some1 could help me explain E would be extremely helpful.

OA : B.

[jnelson0612]

(E) Although the frequency of accidents is greater on Southern Airways, on both airlines the proportion of flights that have accidents is very small.

I am unable to understand wht E is trying to say. Thats wht I have chosen as my ans. Its wrong.
Second option was correct. But if some1 could help me explain E would be extremely helpful.

OA : B.

E means that both airlines have a very low rate of accidents, but the rate of accidents is slightly higher on Southern Airways. I hope that makes sense.

[s.ashwin.rao]

I think something is major miss here. The OA is B.

Check
http://www.beatthegmat.com/air-dacentaria-s-t40682.html
http://gmatclub.com/forum/cr-traveler-28971.html

Even I selected E first and still not how the OA is B? Could someone kindly clarify?

Further I think this question is related to esteria-vs-burdistan-t12225.html

[RonPurewal]

Even I selected E first and still not how the OA is B? Could someone kindly clarify?

choice (e) is irrelevant, since the issue at hand has nothing to do with absolute safety (i.e., as represented by the actual accident rates); the issue deals only with relative safety (= which airline is safer than which other one, regardless of the absolute size of the numbers).

basically, the short version of this argument is "Southern has a higher accident rate overall; therefore, my flight on Southern must be more dangerous."
choice (b) is correct because it breaks that connection: it explains Southern's accident rate by pointing out that Southern's other flights are operated under more dangerous conditions, thereby producing the higher average accident rate. since the current flight in question is not operated under the same dangerous conditions, that higher average is no longer meaningful.

Further I think this question is related to esteria-vs-burdistan-t12225.html

the resemblance between those two problems is not very strong. you could say that they are related on a very general level -- both of them deal with different ways to find exceptions to an assumption that some statistic is related to some other statistic -- but i'm having a hard time seeing how such a vague relationship could help you solve either of these problems upon having seen the other one.

[s.ashwin.rao]

Thanks a ton Ron.

I get the logic now and by the connection I mean both these questions use alternate reasoning for weakining.

[jnelson0612]

Good. :-)

[jp.jprasanna]

Even I selected E first and still not how the OA is B? Could someone kindly clarify?

choice (e) is irrelevant, since the issue at hand has nothing to do with absolute safety (i.e., as represented by the actual accident rates); the issue deals only with relative safety (= which airline is safer than which other one, regardless of the absolute size of the numbers).

basically, the short version of this argument is "Dacentaria has a higher accident rate overall; therefore, my flight on Dacentaria must be more dangerous."
choice (b) is correct because it breaks that connection: it explains Dacentaria's accident rate by pointing out that Dacentaria's other flights are operated under more dangerous conditions, thereby producing the higher average accident rate. since the current flight in question is not operated under the same dangerous conditions, that higher average is no longer meaningful.

Hello Ron - One question with the above statement, I think the prompts says " Southern Airways has a far worse safety record than Air Dacentaria over the past few years " and " I will choose it (Air Dacentaria) over Southern Airways for my flight from Pederton to Dacenta, since it is worth paying extra to have a safer flight "

So to weaken we have to chose an answer choice that will show Southern Airways will be better than Air Dacentaria to travel from Pederton to Dacenta! - I have highlighted your statement above in blue which sort of contradicts my understanding.

Now option B says

"Most Southern Airways flights, but not its flight from Pederton to Dacenta, use Sarmouth airport, which because of its mountainous location is one of the world's most dangerous"

So can we assume that Air Dacentaria uses Sarmouth airport, which is the most dangerous airport???? I think this is little too much to assume but on the other hand there aren't any other ans choice even close, but took about 2.10 min to complete because of the aforementioned assumption. Please help.

[RonPurewal]

So to weaken we have to chose an answer choice that will show Southern Airways will be better than Air Dacentaria to travel from Pederton to Dacenta!

no, that's too extreme. you just have to show that southern airways isn't more dangerous.

if you want to weaken the idea that X is more than Y, you don't have to show that Y is more than X.

So can we assume that Air Dacentaria uses Sarmouth airport, which is the most dangerous airport????

that's a lot of question marks.

you don't have to make this assumption. in fact, you don't have to assume anything about air dacentaria at all -- you just have to weaken the idea that the southern airways flight is dangerous.
this answer choice states that most southern airways flights are more dangerous, because of the use of this particular airport, but that the particular flight our traveler is considering is not more dangerous.
that's enough to break the connection -- in other words, it's enough to show that the overall higher danger of southern airways' flights is irrelevant to this particular flight.

[jyothi h]

Even I selected E first and still not how the OA is B? Could someone kindly clarify?

basically, the short version of this argument is "Dacentaria has a higher accident rate overall; therefore, my flight on Dacentaria must be more dangerous."
choice (b) is correct because it breaks that connection: it explains Dacentaria's accident rate by pointing out that Dacentaria's other flights are operated under more dangerous conditions, thereby producing the higher average accident rate. since the current flight in question is not operated under the same dangerous conditions, that higher average is no longer meaningful.

Oh, I believe , you meant to write "southern airways" instead of "Dacentaria" .

[RonPurewal]

you are right, i switched them. thanks. i'll go edit that post.

[sid090188]

But what is the conclusion here.I was not able to figure it out in the argument. I took it as

It is worth paying extra to have a safer flight.

[tim]

Take a look at Ron's post fourth from the top. He has greatly simple find the argument, and you can identify the conclusion as the part that follows the word "therefore" in his simplified version of the argument..

[sauabhr686]

Hi Ron,
I am still not able to eliminate option E. To weaken the argument, we have to prove that southern airways is as safe as Dacentria or southern airways is safer than Dacentria. Doesn't option E mean that both flights are equally safe and hence weaken the argument????
Please help!!!



Saurabh

[RonPurewal]

Hi Ron,
I am still not able to eliminate option E. To weaken the argument, we have to prove that southern airways is as safe as Dacentria or southern airways is safer than Dacentria. Doesn't option E mean that both flights are equally safe and hence weaken the argument????

well, no, it doesn't. in fact, choice E explicitly acknowledges that the proportions are NOT equal.
the fact that they are both 'small' does nothing at all to change this.

[RonPurewal]

analogy:
Drug A causes death in a higher proportion of patients than drug B does. So I would rather take drug B, even though it's more expensive.

choice E is like saying 'hey dude, both death rates are low' (e.g., 1 death in 10,000 people for drug A, versus 1 death in 100,000 for drug B).

you should be able to see why this doesn't affect the argument.
almost certainly, I ALREADY KNOW that both rates are low... otherwise i wouldn't be willing to take either one of them!

likewise, common sense says the person here ALREADY KNOWS that both accident rates are low. (he/she is clearly a very risk-averse individual; if the rates were high in absolute terms then (s)he simply wouldn't fly at all.)