Nitrogen dioxide is a pollutant emitted by automobiles. Catalytic conv

Question

Nitrogen dioxide is a pollutant emitted by automobiles. Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all new cars in Donia since 1993, and as a result, nitrogen dioxide emissions have been significantly reduced throughout most of the country. Yet although the proportion of new cars in Donia's capital city has always been comparatively high, nitrogen dioxide emissions there have showed only an insignificant decline since 1993.

Which of the following, if true, most helps to explain the insignificant decline in nitrogen dioxide emissions in Donia's capital city?

(A) More of the cars in Donia's capital city were made before 1993 than after 1993.
(B) The number of new cars sold per year in Donia has declined slightly since 1993.
(C) Pollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993.
(D) Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.
(E) Most car trips in Donia's capital city are too short for the catalytic converter to reach its effective working temperature.

Skientist · Accepted Answer

At first glance A is attractive, however this is answer is wrong for a similar reason that percent-style answers are often wrong. Take the following scenario with regard to A): the country folk reduce their pre-1993 car population from 100% to 70%, which creates a significant reduction in nitrogen pollution.

So far so good, this scenario doesn't deviate from the conditions in the argument.

Then say the city slickers do the same, but even more so, from 100% to 51%.

Again this is fine, the argument says that the city slickers are more likely to buy new cars.

So in the above scenario, we satisfy all the condition of the argument. We have also satisfied A) because there are 51% 'old cars' in the city, which means there are  more  old cars than new. However, given that we see a  significant  drop in pollution nationally with a 0% to 30% increase in new cars, shouldn't we expect to see a much greater improvement in the city if we have 0% to 49% uptake of new cars? This argument actually takes us the other way! A) cannot be correct because it brings us no closer to bridging the discrepancy.

For those that are interested, E) is correct because it bridges the gap between the 'expected' and the actual. It does so by accounting for the increase in new cars in the city, while offering a reason why this hasn't had an effect. The reason being that new cars require a minimum distance to be eco-friendly and this distance is rarely reached. In other words, the solution is ineffectual.

Hope that helps!
B.

KarishmaB · Answer

Look, there are two different things. One is ' new information '. Your options playing the role of premises provide new information to strengthen the conclusion/weaken the conclusion/explain the paradox.
The other thing is ' out of scope ' i.e. when the option discusses something irrelevant to the argument. e.g. if I say "The country Monia's capital has witnesses a massive decline in nitrogen dioxide emissions since they introduced catalytic converters." This is out of scope because what happens in country Monia has nothing to do with what happens in country Donia.

The information in red is new information which explains the paradox that though in Donia nitrogen dioxide emissions have reduced significantly, they haven't reduced in Donia's capital. In Donia's capital, people don't travel long distances and hence the catalytic converters doesn't reach their effective working temperature.

amitdgr · Answer

Is it E ?

zaarathelab · Answer

A. More of the cars in Donia’s capital city were made before 1993 than after 1993--- Good incorrect choice. But we are still told that there are comparatively high no. of new cars, therefore a significant drop should have been there 
B. The number of new cars sold per year in Donia has declined slightly since 1993----- weakens. If it has declined only slightly then a significant decline in emissions should have been seen.  
C. Pollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993.--------- out of scope  
D. Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.  Does not explain the contrast 
E. Most car trips in Donia’s capital city are too short for the catalytic converter to reach its effective working temperature------ CORRECT

zuberahmed · Answer

Hi,

Most car trips in Donia’s capital city are too short for the catalytic  converter to reach its effective working temperature

Dont you think the information marked above in red is out of bounds of the stimulus. If so how can option E be correct?

thevenus · Answer

it is very well mentioned that "..............Yet although the proportion of new cars in Donia's capital city has always been comparatively high"  
so, (A) can not be considered correct.

(E) wins because the catalytic converter installed in the new cars are not effective , so the purpose of emission reduction failed.

Krishchamp · Answer

Can someone please explain me to get the crux of this argument. I also wanted to know how other options are eliminated and how the correct answer is correct.

GMATNinja · Answer

One very important thing to keep in mind is that we are not being asked to evaluate an argument.

The passage is giving us seemingly contradictory data:

Since 1993, nitrogen-dioxide-emissions-reducing converters have been required in all new cars, and the proportion of new cars in the capital has always been comparatively high. 
  Yet, since 1993, nitrogen dioxide emissions in the capital city have showed only an insignificant decline.

We are asked which of the answer choices (if true) would most explain this contradiction.

Does this clarify previous posts, or help you think more clearly about how to eliminate choices?

SAIgmat09 · Answer

can anyone explain why each option is right or wrong? If catalytic converters were already installed, that would explain why the decrease in emissions is not significant. Doesn't it? Please help 😏

Posted from my mobile device

CrackverbalGMAT · Answer

The argument gives us the following information

Nitrogen dioxide- pollutant emitted by automobiles
2) Catalytic converters- designed to reduce nitrogen dioxide emissions
3) Catalytic converters- have been required in all new cars in Donia since 1993
 Result- nitrogen dioxide emissions reduced significantly throughout most of the country

YET 
Although the proportion of new cars in Donia's capital city has always been comparatively high, nitrogen dioxide emissions there have not showed any significant decline since 1993.

Inspite of having the Catalytic converters in all cars in Donia to reduce nitrogen dioxide emissions, nitrogen dioxide emissions have not showed any significant decline in Donia’s capital city. How? Why?

We need to find an option that would resolve the paradox presented in the argument

A) More of the cars in Donia's capital city were made before 1993 than after 1993- This cannot be considered correct as the argument says that the proportion of new cars in Donia's capital city has always been high-  Eliminate A

B) The number of new cars sold per year in Donia has declined slightly since 1993- The conclusion talks about the nitrogen dioxide emissions in Donia’s capital -  Eliminate option B

C) Pollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993- This talks about other pollutants that have been reduced significantly in Donia since 1933 and not nitrogen dioxide -  Eliminate option C

(D) Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.- So how does this resolve the paradox? It doesn’t-  Eliminate option D

(E) Most car trips in Donia's capital city are too short for the catalytic converter to reach its effective working temperature.

This gives the answer as to  why  despite having the Catalytic converters (to reduce nitrogen dioxide emissions) in all cars in Donia, nitrogen dioxide emissions have not showed any significant decline in Donia’s capital city. For the Catalytic converters to work, it has to reach its effective working temperature. But most car trips in Donia's capital city are too short for the catalytic converter to reach its effective working temperature. Hence nitrogen dioxide emissions there have not showed any significant decline since 1993. Option E is the correct answer.

Vishnupriya
CrackVerbal Prep Team

Hoozan · Answer

EducationAisle

The argument states:  "Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all new cars in Donia since 1993.  Although the proportion of new cars in Donia's capital city has always been comparatively high ,"

(A) states:  "More of the cars in Donia's capital city were made before 1993 than after 1993."

How is (A) possible? isn't it contradicting the information given in the argument?

EducationAisle · Answer

Hi Hoozan, the argument says:

the proportion of new cars in Donia's capital city has always been   comparatively   high

So, the argument is just comparing the proportion of new cars in Donia vs Donia's capital city.

So, as per A, it is possible that (say) 40% of the cars in Donia's capital city were made before 1993 than after 1993, whereas in Donia overall, 30% of the cars in Donia were made before 1993 than after 1993.

So, A isn't really contradicting the premise.

Hoozan · Answer

Susy426 · Answer

We need to find what makes Donia's City different from the rest of the country. D is wrong because it's talking about all Donians, not Donians who live in the Capital.

freemanfanmao · Answer

I feel like this is a really poorly constructed question.

First of all, a key piece of information given in the question-"Yet although the proportion of new cars in Donia's capital city has always been comparatively high"-is very confusing and introduces ambiguity. "New Car" can be interpreted in many different ways, even in the auto industry it is not a typically well defined term. "New Car" can mean new car sales each year, it can mean whether the car was bought new or used (in this case a car bought 10 years ago as new can still be a new car), it can mean new in relative terms (i.e. 2-year old is considered new but not 10-year old), it can also have many other meanings depending on how it's interpreted. Secondly, the meaning of the word "comparatively" is also unclear, presumably it means comparative to Donia's national level new car proportion, but it can also be interpreted as comparative to old car proportion in Donia's capital.

Lastly, I have yet to see a convincing explanation on why answer choice D is wrong, other than the one quoted below. As D seems to offer a pretty good logical explanation that, if many cars before 1993 already had the converter installed then having new cars with the converter will not have a big impact on the NO2 emission. All the experts' replies so far seem to miss the point, and the one below is the only sensible explanation I could find in this thread.
 
And if this is truly the intention of the questioner, then this goes back to my point that this question is just poorly constructed. As it offers a logically sound answer but traps you with small wording nuances.

I'm respectfully calling out all GMAT verbal experts to confirm my reasoning here regarding answer choice D, or to tell me that I was being completely nonsensical and subsequently give an alternative explanation.

Thanks.

krndatta · Answer

KarishmaB  Ma'am,

The above line means that  the number of news cars in Donia / Total no. of cars in Donia.  Right?

If this proportion is high, then the info in option A contradicts the info in the question stem.

Is my reasoning correct?

freemanfanmao · Answer

Not necessarily, it can mean new car proportion in D's capital is higher than new car proportion in D at national level. It's unclear what the question means by "new car" and "comparatively", making this question confusing and ambiguous. Presumably "new car" means new car sales each year, and "comparatively" means comparative to D's national level.

GMATNinja · Answer

"...it offers a logically sound answer but traps you with small wording nuances..." - That's GMAT CR in a nutshell! That's why reading precision is so important, as discussed in  this article  and every CR video we've ever done, including  our most recent CR babble .

The explanation you quoted is spot-on. The passage very clearly indicates that there's a big difference between (1) what happened in the capital and (2) what happened in most of the country. Why is it that NO2 emissions barely declined in the capital while NO2 emissions were  significantly reduced  throughout most of the country?

(D) fails to explain that difference. All else being equal, we would expect (D) to have the same impact on emissions everywhere in the country (including the capital). After all, if (D) is true, then ANY car (new or old) can have a catalytic converter and thus can have lower NO2 emissions. That means that the new tech should lower NO2 emissions everywhere, regardless of the proportion of pre-1993 vehicles... so why the discrepancy in the data?

(E) is the only one that explains the difference, so it's the only choice that works.

I hope that helps!

freemanfanmao · Answer

Thanks Charles for the reply and confirmation. So if (D) said "Many Donians  in the capital  who own cars made before 1993 have had catalytic converters installed in their cars.", then it would be a possible correct answer to the question right?

Thanks.

Nitrogen dioxide is a pollutant emitted by automobiles. Catalytic conv

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Nitrogen dioxide is a pollutant emitted by automobiles. Catalytic conv

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

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Perfect 805 Score Debrief by Julia

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