Critical Reasoning--Set-23-Q-38

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Critical Reasoning--Set-23-Q-38

by prachich1987 » Sat Dec 11, 2010 10:47 am
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
34
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.

The answer is A.Can someone explain why E is the right answer & A is wrong?

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by shovan85 » Sat Dec 11, 2010 11:31 am
prachich1987 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
34
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?

The answer is A.Can someone explain why E is the right answer & A is wrong?
Question Type: Paradox

Paradox: In the city all new cars are with catalytic converters and yet nitrogen dioxide emissions have not gone down though the function of the catalytic converts is to reduce nitrodgen dioxide emissions.

"Why" is it so is the paradox. We need to resolve this paradox.

Options:

A. More of the cars in Donia's capital city were made before 1993 than after 1993.

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

Option A goes against the Passage. Incorrect.

B. The number of new cars sold per year in Donia has declined slightly since 1993.

Still new cars are sold. Their declination does not help to say why catalytic converters are not fruitful. Incorrect.

C. Pollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993.

We need nitrogen dioxide to be reduced not other pollutants.

D. Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.

Irrelevant. Its good that these were installed before but they are not helping in reducing nitrogen dioxide. And this option does not help to say us WHY. Incorrect.

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

Trips in the capital city are so short that the catalytic converter doesn't even get time to operate. So, although most of the cars in the capital city are new and installed with these converters, the trips are so short that the converters don't get time to function.

Answer is E
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by santoshs » Sat Dec 11, 2010 12:46 pm
prachich1987 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
34
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.

The answer is A.Can someone explain why E is the right answer & A is wrong?
A : Correct
It is been already mention in passage that all new car should be fitted with catalytic converter (Line 2) but their is no mention of fitting catalytic converter for old cars. Option A gives as premises that their are more old car in Donia than new car, thus their are more car without catalytic converter in Donia. Hence introduction of few new car with catalytic converter have insignificant effect on level of atmospheric Nitrogen dioxide in Donia.

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by rkanthilal » Sat Dec 11, 2010 2:21 pm
I agree the answer is E...

Between (A) and (E)...

A. "More of the cars in Donia's capital city were made before 1993 than after 1993." Incorrect. The question stem indicates that we are supposed to assume the answer choices are true. In this case, the fact that an answer contradicts the passage is not a sufficient reason to eliminate that answer.

That said, I don't believe this answer choice contradicts the passage. The passage states that "the proportion of new cars in Donia's capital city has always been comparatively high". This is a relative statement not an absolute one. This statement from the passage compares the proportion of new cars in the capital city to to the proportion of new cars outside the capital city.

Answer choice (A) implies that more than 50% of the cars in the capital city were made before 1993. Let's assume, for example, that 51% of the cars in the capital city were made before 1993 and 90% of the cars outside the capital city were made before 1993. In this case the statement that "more of the cars in Donia's capital city were made before 1993" is true and it is consistent with the passage's claim that "the proportion of new cars in Donia's capital city has always been comparatively high".

In my opinion, this answer is incorrect because it does not sufficiently explain the paradox. If before 1993 very few cars had catalytic converters and now less than 50%, say 49%, of the cars have them, then one would expect there to be a reduction in emissions. This answer does nothing to explain why there is an "insignificant reduction".


E. "Most car trips in Donia's capital city are too short for the catalytic converter to reach its effective working temperature." Correct. As Shovan mentioned in his posting, this answer implies that the catalytic converters on the cars in the capital city don't work as intended because the car trips are so short. This answer sufficiently resolves the paradox.

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by santoshs » Sat Dec 11, 2010 10:04 pm
Oh, got it option A is a classic example of switching error in CR. Thanks

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by prachich1987 » Sat Dec 11, 2010 10:08 pm
santoshs wrote:Oh, got it option A is a classic example of switching error in CR. Thanks
Can you plz explain what is a switching error?