Many households have replaced at least one of their

Doubt was between A&D because
D said some electricity and
in A the gasoline was used only to produce the car (as compared in gasoline cars the gasoline was being consumed throughout the life of the care)

I re read both of them and was about to choose D. But i read it again to confirm my answer.
This is when I saw the word more in option. From this I concluded that gasoline used to manufacture the car was more than the gasoline cars would use throughout thier lifetime.

Please explain what is the flaw in my reasoning

I agree ... A should be the answer ... more obviously has more effect than some

D,

the question is not asking to compare the total amounts of gasoline used. If you read the argument carefully.

It is thus clear to see that less gasoline is being used as a result of the operations of these households than they would have used if they had maintained their original cars.

So apparently you should not care whether to produce the cars more gasoline was used or not. The only thing that casts a doubt on the argument is option D.

I am not expert but trying to take a shot at it-

if electric car production takes 10 gallon more per car but traditional car use 20 gallon in its life time, than it does weaken the argument. So A does not cast enough doubt.
D is saying some gasoline is being used to generate electricity, which means it is not saving as much as projected.

The official answer is D.

You want an answer that says that less gasoline will not necessarily be the result of driving electric cars. See explanation for each answer choice below.

[quote="BeckyRobinsonTPR"]Many households have replaced at least one of their traditional gasoline powered cars with electric cars. It is thus clear to see that less gasoline is being used as a result of the operations of these households than they would have used if they had maintained their original cars.

which of the following, if true casts the most doubt on the argument above?

A) More gasoline was used to produce the new electric cars than was used to produce the traditional cars. Gasoline used to PRODUCE the cars does not figure into use for operation. The cars have already been produced thus it does not weigh into gasoline consumption as a result of the operation.

B) Many of the households that have replaced at least one of their traditional cars have decreased the amount of miles they drive.This does not weaken the conclusion, and actually strengthens it slightly in that if they have decreased the miles, then it could be true that they used less gasoline

C) Some of the households that have replaced at least one of their traditional cars use their electric car more often than their traditional car.using the electric car more often would mean not using the gas powered car, thus it does not weaken the conclusion and could in fact strengthen

D) Electric companies use gasoline powered generators to produce at least some of the electricity they provide to their customers. if gasoline is used to produce electricity then that means that even using the electric car would result in consumption of gasoline. This weakens the conclusion because it shows that even though the households are not putting gasoline in their car, gasoline is being used to power it.

E) A fully charged electric car travels fewer miles than a gasoline powered car with a full tank. This does not weigh in the issue of how much gasoline is used.[quote]

No D is correct because in A

A) More gasoline was used to produce the new electric cars than was used to produce the traditional cars.

In D

D) Electric companies use gasoline powered generators to produce at least some of the electricity they provide to their customers.

This makes a huge difference. After all, we do not care about the comparison how was the production between the old and the ne car.

Nice question

It was a tough split for me between (A) and (D). I chose (D) in the end because (A) is a one time expenditure of gas whereas (D) is a constant use of gas which can make up for the change in cars.

But it is not 700 level, is it? I found the actual GMAT CR much harder even harder than the questions in GMAT prep. I think GMAT Prep should be upgraded. What do you guyz think?

Conclusion clearly states "thus clear to see that less gasoline is being used as a result of the operations..."

Thus, we are concerned with the recurring use of gasoline going forward and usage from past.

Thus, D

Agree with D.Great explanation provided by TPR representative,Becky Robinson!

Clearly D is the right answer: (2:17)

"being used as a result of the operations of these households"

A) More gasoline was used to produce the new electric cars than was used to produce the traditional cars.
Manufacturing does not counts into operations of these households.. though it was a tempting option ... keywords plays crucial roll in rejecting such a choice.


D) Electric companies use gasoline powered generators to produce at least some of the electricity they provide to their customers.
Yes above choice clearly raise doubt that gasoline used as a result of the operations of these households is not reduced compared to previous condition.

Isn't this a little bit reaching too far?
The question is did the consumption of gas decline due to the families buying these electric cars.
If, for a regular car, 1 L of gas lasted for 10 KM, and for an electric car, 1 L of gas produces enough electricity to drive 20 KM, than the consumption was still reduced!
No?

we need an answer that would show why the consumption of gasoline has not decreased.
A talks about one-time usage, when the cars are manufactured. still not a good weakener, as the gasoline saved might be > than the gasoline used during the manufacturing process.
B - this would strengthen the argument.
C - some - ambiguous, as it might be 1-100. clearly, if people use more often/drive more, then they do not save much. moreover, comparison is between usage of regular cars vs. electric cars. so not what we need.
D - looks good. to generate power, we need gasoline, thus, the consumption is not decreased.
E - irrelevant

Yes, and the other problem with A is that it addresses the production, not the consumption, of electric cars.

Are we not assuming while discarding option B (and saying that it strengthens the argument) that the decrease in the amount of miles driven is due to the replacement of gasoline powered cars with electric ones? If the distance driven was going to be reduced regardless then the decrease in consumption of gasoline would've happened even without the replacement?

B seems like the tricky answer.

D says that electric companies use gasoline to produce "at least some" electricity but that does not mean that gasoline is being used more or less compared to when gasoline powered cars were being used!


Sent from my iPhone using GMAT Club Forum mobile app

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Explanation by Gian.

IMO D. Nice Question, Let me try.

Premise: Many households have replaced atleast one of their traditional gasoline cars with electric cars.

Conclusion: Thus, consumption of gasoline will be reduced because of the replacement operation.

B & C: Strengthens the conclusion
E: No effect on the conclusion

A: This choice is going beyond the scope. Because once cars are produced, the gasoline consumption depends on the type of car used extensively. What if, people are using electric cars on a daily use and traditional cars on weekends. The gasoline consumption v'll be reduced in the long run & this choice supports the author's point.

So, even if, more gasoline was initially required to produce the electric cars, it can be considered an initial investment.
Choice A doesn't hit the central assumption of the author: That after the replacement operation is done, gasoline consumption v'll reduce because more and more people will drive electric cars.

Coming to Choice D: More Electric cars on the roads means they need to be charged also on a daily or weekly basis. So, electricity companies v'll provide electricity to charge these electric cars but WAIT, they v'll use gasoline powered generators to produce that electricity. So, is the gasoline consumption reduced ? NO
It hurts the author's conclusion.
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It is a good explanation. But.
So, Gian says that in optopn A we have consider the initially required gasoline for production of electric cars an initial incestment, but in a long run gasoline consumption will be reduced and it supports the aauthor's point.

Ok. Option D says that "Electric companies use gasoline powered generators to produce at least some of the electricity"
Sure. Lets assume that this "some" is equal to 5%. And another 95% is produced by solar generator. And these 5% will be never bit up the amount of gasoline that the owners of electricity cars saved by buying these cars.
So, actually it strenghens the author's conlusion, not casts doubt on it.

How are you, people, who chose the option D, so sure that this is the clear answer?

Now, about the accent on words "as a result of the operations of these households". Some of you did it, some not.
I did it, an I chose option B. Witt the same reasoning as an author 1 post above me, asavrud, has
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Are we not assuming while discarding option B (and saying that it strengthens the argument) that the decrease in the amount of miles driven is due to the replacement of gasoline powered cars with electric ones? If the distance driven was going to be reduced regardless then the decrease in consumption of gasoline would've happened even without the replacement?

B seems like the tricky answer.

D says that electric companies use gasoline to produce "at least some" electricity but that does not mean that gasoline is being used more or less compared to when gasoline powered cars were being used!
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Where are we wrong?

I chose option B. This says that many of the families that have switched at-least one of their cars to electric model, have also reduced the total miles they drive. 'the families have reduced the total miles they drive' gives a reason independent to result in reduced consumption of gasoline (even if they were driving the un-switched gasoline powered cars)

On the other hand in option D, the phrase "at least some of the electricity" points to gaping loopholes in the answer choice. e.g. a fractional use of gasoline (0.1% of the current use per car, given the number of miles driven remains same for all converted cars) should not cause an increase in gasoline consumption.