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68%
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In theory, the Habbendorf rotary engine could be a great racing engine, but in practice, it is not. The reason is that the available fuels do not have sufficient octane to obtain maximum performance from the engine.
The answer to which of the following questions would be most relevant to evaluating the adequacy of the explanation given above for why the Habbendorf rotary engine is not a great racing engine?
A. If the Habbendorf rotary engine were to operate at maximum performance levels, how would its performance compare to that of an engine recognized as a great racing engine?
B. At what level of octane in its fuel does the Habbendorf rotary engine achieve maximum performance?
C. What levels of speed, acceleration, and efficiency must an engine display in order to be considered a “great racing engine”?
D. Could a Habbendorf rotary engine be modified so that it is able to achieve maximum performance with the fuels currently available?
E. If a car equipped with a Habbendorf rotary engine were to race against a comparable car equipped with a great racing engine, by how much would the performance of the great racing engine surpass that of the Habbendorf rotary engine?
The answer to which of the following questions would be most relevant to evaluating the adequacy of the explanation given above for why the Habbendorf rotary engine is not a great racing engine?
A. If the Habbendorf rotary engine were to operate at maximum performance levels, how would its performance compare to that of an engine recognized as a great racing engine?
B. At what level of octane in its fuel does the Habbendorf rotary engine achieve maximum performance?
C. What levels of speed, acceleration, and efficiency must an engine display in order to be considered a “great racing engine”?
D. Could a Habbendorf rotary engine be modified so that it is able to achieve maximum performance with the fuels currently available?
E. If a car equipped with a Habbendorf rotary engine were to race against a comparable car equipped with a great racing engine, by how much would the performance of the great racing engine surpass that of the Habbendorf rotary engine?
Source: McGraw Hill GMAT
Difficulty Level: 750
Difficulty Level: 750
Posts: 2
I think it's D which is evaluating the argument logically.
Sent from my iPhone using GMAT Club Forum
Sent from my iPhone using GMAT Club Forum
Hi, can someone please post an explanation for this question?.... I am stuck.
I want to understand the logic of how should i eliminate each option in this question and arrive at the right answer.
Hi everyone..
Went for D...but on careful observation of A...it can be understood why A is correct.
A actually goes an extra step .
The basic is to compare the theoritical performance with actual...Then comes the reason
Option A notes that Habbendorf rotary engine at "maximum performance levels" if compared to "a great racing engine"(in which all the criteria required to consider a racing engine to be "great" has been taken care of) can clearly indicate how good Habbendorf rotary engine is.
Went for D...but on careful observation of A...it can be understood why A is correct.
A actually goes an extra step .
The basic is to compare the theoritical performance with actual...Then comes the reason
Option A notes that Habbendorf rotary engine at "maximum performance levels" if compared to "a great racing engine"(in which all the criteria required to consider a racing engine to be "great" has been taken care of) can clearly indicate how good Habbendorf rotary engine is.
gmatexam439
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gmatexam439 This is what i understand from the question.
The argument runs on two grounds, viz one on the theoretical and other on the practical side.It is already mentioned in the argument that the engine is practically not so great since it has got issue with the octane number of the fuel.So there nothing much to be discussed about the practical aspects {because we already know why practically it is not a great engine} and now we are left with only one question .........."whether theoretically it is a great engine or not?". For that we need to assume our engine working under the ideal condition, that is the engine working on the fuel with ideal octane number and then compare the engine's performance with other great engine.
The argument runs on two grounds, viz one on the theoretical and other on the practical side.It is already mentioned in the argument that the engine is practically not so great since it has got issue with the octane number of the fuel.So there nothing much to be discussed about the practical aspects {because we already know why practically it is not a great engine} and now we are left with only one question .........."whether theoretically it is a great engine or not?". For that we need to assume our engine working under the ideal condition, that is the engine working on the fuel with ideal octane number and then compare the engine's performance with other great engine.
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Hi pkm9995109794,
This is somehow making sense to me. Based on your explanation "A" does fit the bill correctly.
Thank you for the post.
Regards
The fuels do not get maximum performance from the engine, thus the engine is not great.
Using POE:
E. Incorrect. It really has nothing to do with the reasoning and knowing how much it might lose by also gives no help. Two engines could be great, but one still has to perform better.
D. Incorrect. How to make the engine better does not matter in how it performs now.
C. Incorrect. Again this really does not address the issue. It might give us a baseline for some (not necessarily all) performance indicators, but the argument here is that the fuel does not get max performance. We also have no idea what performance the engine currently gets.
B. Incorrect. This lets us know what fuel is needed but doesn't tackle the question of what is the problem with the fuel now.
A. Correct.
Using POE:
E. Incorrect. It really has nothing to do with the reasoning and knowing how much it might lose by also gives no help. Two engines could be great, but one still has to perform better.
D. Incorrect. How to make the engine better does not matter in how it performs now.
C. Incorrect. Again this really does not address the issue. It might give us a baseline for some (not necessarily all) performance indicators, but the argument here is that the fuel does not get max performance. We also have no idea what performance the engine currently gets.
B. Incorrect. This lets us know what fuel is needed but doesn't tackle the question of what is the problem with the fuel now.
A. Correct.
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Official Explanation
The explanation given in the passage relies on the assumption that if the rotary engine could obtain maximum performance, then it would be a great racing engine. Answer A directly questions that assumption. The question in E is incorrect because it focuses on whether or not the rotary engine is a great racing engine, rather than on the explanation given in the passage. The question in D goes outside the scope of the explanation given in the passage, and B and C do not directly address the given explanation.
ANSWER: A
The explanation given in the passage relies on the assumption that if the rotary engine could obtain maximum performance, then it would be a great racing engine. Answer A directly questions that assumption. The question in E is incorrect because it focuses on whether or not the rotary engine is a great racing engine, rather than on the explanation given in the passage. The question in D goes outside the scope of the explanation given in the passage, and B and C do not directly address the given explanation.
ANSWER: A
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Sajjad1994
This is an excellent question.
The question asks which option is relevant to evaluating the "adequacy of the explanation"
C is incorrect because whether Habbendorf rotary engine could be a great racing engine is not our objective. Our objective is whether the explanation by author is valid or not.
A allows us to test the adequacy of the explanation by the author.
A is Correct
Posts: 334
The OE is not convincing to me, cuz the explanation is to why H engine is not a great racing engine (in practice), but A is saying why H engine is not a great racing engine (in theory), so I think A is irrelevant.
Posts: 14
I also marked D, but now when I look at it, A MAKES SENSE
Option D tells that whether the engine can be modified and run on currently available fuel. This doesn't help us determine whether the reasoning given "lack of octave fuel" is adequate or not. Either the answer can be a Yes - but I don't know if it will give a supercar performance or not. Same goes for a No.
If it was something like that "If some special octave fuel (required by car) was recently discovered and testing can be done on car" - this would have made sense since now we can gauge whether lack of fuel is the only reason for it no being a supercar
Option A tells. that we can put some other fuel and test the car's running parameters to see if it qualifies as a supercar or not. If the car qualifies as a supercar after running it, it means that given logic of lack of fuel as the reason for car not being adequate was wrong.
Option D tells that whether the engine can be modified and run on currently available fuel. This doesn't help us determine whether the reasoning given "lack of octave fuel" is adequate or not. Either the answer can be a Yes - but I don't know if it will give a supercar performance or not. Same goes for a No.
If it was something like that "If some special octave fuel (required by car) was recently discovered and testing can be done on car" - this would have made sense since now we can gauge whether lack of fuel is the only reason for it no being a supercar
Option A tells. that we can put some other fuel and test the car's running parameters to see if it qualifies as a supercar or not. If the car qualifies as a supercar after running it, it means that given logic of lack of fuel as the reason for car not being adequate was wrong.
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