Nitrogen Dioxide in Donia (GPREP)

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trumpet1184: Newbie | Next Rank: 10 Posts; Posts: 7; Joined: Tue Jun 23, 2009 8:38 pm

by trumpet1184 » Fri Jul 17, 2009 9:57 pm

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 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.

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Source: Beat The GMAT — Critical Reasoning | Fri Jul 17, 2009 9:57 pm

vcgmat: Junior | Next Rank: 30 Posts; Posts: 21; Joined: Mon Feb 16, 2009 6:53 pm

by vcgmat » Fri Jul 17, 2009 10:03 pm

IMO E

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madhur_ahuja: Master | Next Rank: 500 Posts; Posts: 435; Joined: Sat May 02, 2009 3:55 am; Thanked: 17 times

by madhur_ahuja » Fri Jul 17, 2009 10:53 pm

Its between A and E, I will go for E

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tohellandback: Legendary Member; Posts: 752; Joined: Sun May 17, 2009 11:04 pm; Location: Tokyo; Thanked: 81 times; GMAT Score:680

by tohellandback » Sat Jul 18, 2009 12:04 am

IMO E
it is between A and E, but in A "more" is not very convincing

The powers of two are bloody impolite!!

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yalanand: Senior | Next Rank: 100 Posts; Posts: 79; Joined: Wed Feb 06, 2008 7:52 am; Thanked: 2 times; GMAT Score:620

by yalanand » Sat Jul 18, 2009 1:02 am

IMO "D"

Since the instrument was already installed in most of the old cars...we can infer that the level of emission is already low...

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trumpet1184: Newbie | Next Rank: 10 Posts; Posts: 7; Joined: Tue Jun 23, 2009 8:38 pm

by trumpet1184 » Sat Jul 18, 2009 11:45 am

I'm sorry I didn't post the answer before. I just learned that answers can be hidden.

The OA is E.

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pandeyvineet24: Legendary Member; Posts: 527; Joined: Mon Jun 02, 2008 9:14 am; Location: Atlanta; Thanked: 17 times

by pandeyvineet24 » Sun Jul 19, 2009 1:17 pm

Should be E.

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mmslf75: Legendary Member; Posts: 503; Joined: Sun Aug 09, 2009 9:53 pmFollowed by: 2 members; Thanked: 31 times

by mmslf75 » Fri Dec 25, 2009 11:40 am

trumpet1184 wrote: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 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.

E is correct here,
If the convertor doesnot reach effectove working temp. then how will the catalytic action come into picture
This will mar the chances of lessening the amout of nitro in atmosp, justifying the "INSIGNIFICANT DECLINE"

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Testluv: GMAT Instructor; Posts: 1302; Joined: Mon Oct 19, 2009 2:13 pmFollowed by: 164 members; Location: Toronto; Thanked: 539 times; GMAT Score:800

by Testluv » Fri Dec 25, 2009 12:16 pm

mmslf is correct.

You should read the question stem first (step 1 of the Kaplan method).

The question stem here tells us that we are dealing with an "explain" or "paradox" question. Therefore, the stimulus will NOT present an argument, and it makes no sense to think about conclusion and assumption. Instead, in paradox questions, the stimulus will present a set of facts out of which will arise a paradox or contradiction or surprise of some sort. Understand what the paradox is, and then go to the answer choices looking for one that will be logically capable of resolving it.

Here, the paradox is that in the capital city there's all these new cars with catalytic converters and yet nitrogen dioxide emissions have not gone down. But the function of the catalytic converts is to reduce nitrodgen dioxide emissions. So, then why the heck did nitrogen dioxide emissions not go down in the capital city?...that's the paradox.

Now, we are ready go to the choices, asking ourselves: "which answer choice will resolve this paradox, relieve this surprise?"

choice E tells us that trips in the capital city are so short that the catalytic converter doesn't even get time to warm up so that it can operate. Oh, so that's it: although most of the cars in the capital city are new and so have these converters, the trips are so short that the converters don't even kick in. That resolves the paradox.

Kaplan Teacher in Toronto

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bigmonkey31: Senior | Next Rank: 100 Posts; Posts: 62; Joined: Sat Jan 02, 2010 1:11 am; Thanked: 3 times; GMAT Score:730

by bigmonkey31 » Mon Mar 01, 2010 10:24 pm

Testluv wrote:mmslf is correct.

You should read the question stem first (step 1 of the Kaplan method).

The question stem here tells us that we are dealing with an "explain" or "paradox" question. Therefore, the stimulus will NOT present an argument, and it makes no sense to think about conclusion and assumption. Instead, in paradox questions, the stimulus will present a set of facts out of which will arise a paradox or contradiction or surprise of some sort. Understand what the paradox is, and then go to the answer choices looking for one that will be logically capable of resolving it.

Here, the paradox is that in the capital city there's all these new cars with catalytic converters and yet nitrogen dioxide emissions have not gone down. But the function of the catalytic converts is to reduce nitrodgen dioxide emissions. So, then why the heck did nitrogen dioxide emissions not go down in the capital city?...that's the paradox.

Now, we are ready go to the choices, asking ourselves: "which answer choice will resolve this paradox, relieve this surprise?"

choice E tells us that trips in the capital city are so short that the catalytic converter doesn't even get time to warm up so that it can operate. Oh, so that's it: although most of the cars in the capital city are new and so have these converters, the trips are so short that the converters don't even kick in. That resolves the paradox.

I can see why E is correct. But can't D be correct as well?

My reasoning: If the cars in the city already had catalytic converters, then the nitrogen dioxide levels would already be low, and thus the requirement imposed in 1993 will NOT have a significant effect on the nitrogen dioxide levels.

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nileshdalvi: Master | Next Rank: 500 Posts; Posts: 171; Joined: Sat Feb 28, 2009 4:59 amFollowed by: 3 members; Thanked: 13 times

by nileshdalvi » Tue Mar 02, 2010 4:09 am

Please read the answer choice carefully. This is one of the basics required to not carelessly tick a wrong answer choice. Does answer choice D mention that only Cars in Donian Captial City had catalytic converters installed previously?. That should answer your question.

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bigmonkey31: Senior | Next Rank: 100 Posts; Posts: 62; Joined: Sat Jan 02, 2010 1:11 am; Thanked: 3 times; GMAT Score:730

by bigmonkey31 » Tue Mar 02, 2010 1:08 pm

Ah, I see it now. I guess I was misinterpreting the entire sentence.. it's amazing what a fresh new day and mind will do to your reading abilities

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delhiboy1979: Master | Next Rank: 500 Posts; Posts: 239; Joined: Wed Feb 11, 2009 2:50 am

by delhiboy1979 » Wed Mar 03, 2010 4:18 am

nileshdalvi wrote:Please read the answer choice carefully. This is one of the basics required to not carelessly tick a wrong answer choice. Does answer choice D mention that only Cars in Donian Captial City had catalytic converters installed previously?. That should answer your question.

Wow, good point

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CaptainM: Senior | Next Rank: 100 Posts; Posts: 46; Joined: Wed Mar 10, 2010 8:54 amFollowed by: 1 member

by CaptainM » Mon Oct 04, 2010 1:07 am

Could someone please explain what's wrong in the following reasoning?

Stimulus says"Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all
new cars in Donia since 1993"......... Yet although the proportion of new cars in Donia's capital city has always been comparatively high...."

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

If more of the cars were made before 1993 then those would not be equipped with converters, leading to insignificant decline in nitrogen dioxide emissions in Donia's capital city.

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g000fy: MBA Student; Posts: 113; Joined: Sat Dec 05, 2009 10:05 pm; Location: West Lafayette; Thanked: 1 times; GMAT Score:700

by g000fy » Mon Oct 04, 2010 11:18 am

CaptainM wrote:Could someone please explain what's wrong in the following reasoning?

Stimulus says"Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all
new cars in Donia since 1993"......... Yet although the proportion of new cars in Donia's capital city has always been comparatively high...."

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

If more of the cars were made before 1993 then those would not be equipped with converters, leading to insignificant decline in nitrogen dioxide emissions in Donia's capital city.

There's a possibility that these cars can be fitted with convertor kits. E is the strongest as it weakens the argument in all cases.

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