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Tricky CR!!

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Tricky CR!!

by jitsy » Wed Dec 22, 2010 9:56 am
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?

Any idea what the right ans could be??
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by fitzgerald23 » Wed Dec 22, 2010 12:25 pm
Where does that question come from? If I had to guess I would answer A, but only because it seems the best of the 5. I cant really justify it much.

Essentially the author is saying that the fuels do not get maximum performance from the engine, thus the engine is not great.

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 doesnt tackle the question of what is the problem with the fuel now.

A. Correct. Like I said above I just find this to be the best of the worst. I would guess that the answer to this question lets us know if the engine is really great or not. If the answer is that it would be subpar under ideal conditions then we know that fuel is not the reason that this is not a great engine. My problem is that the passage reads that the reason that its not a great engine is because it doesnt get max performance, in essence saying to be a great engine you must get maximum performance. It doesnt say that max performance is needed in order for it to be a great engine (i.e. maybe it can operate at 90% and still outperform most great engines).
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by jitsy » Wed Dec 22, 2010 1:58 pm
Really appreciate the detailed response.

This question is from the McGraw Hills GMAT 2011. The book does go with A too. Just a little doubt which your explanation sorted out.

Thanks again.
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by nk_81 » Sun Jan 02, 2011 4:30 am
Why not B.

Can someone please break the question down for me?
NK
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by jitsy » Thu Jan 06, 2011 11:20 am
Hi nk_81,

The answer would have been B had the question stem asked "The answer to which of the following questions would be most relevant to evaluating the conclusion?"

That is, if were supposed to find out if the octane levels are really less, then we would have asked "ok, if its really that less, what octane levels are reqd. for max performance?" And the answer would have then helped us find out if the present octane levels are less than what the question answered.

BUT, the question here asks whether the reason that 'octane levels are not sufficient to achieve max perf' is ADEQUATE.

For that, we have to assume that the octane levels are ok and then find out that if "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?
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by mundasingh123 » Sun Jan 09, 2011 6:10 am
Hi whats the source?
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