Introducing a catalytic converter not only reduces by 30% the harmful

Question

Introducing a catalytic converter  not only reduces by 30% the harmful gases in the exhaust, but also reduces the required time of reaching the top speed .

A. not only reduces by 30% the harmful gases in the exhaust, but also reduces the required time of reaching the top speed

B. not only reduces the harmful gases in the exhaust by 30%, but also the required time to reach the top speed

C. not only reduces the harmful gases by 30% in the exhaust, but the required time to reach the top speed is also reduced

D. reduces not just the harmful gases in the exhaust by 30%, but also the required time to reach the top speed

E. reduces not the harmful gases in the exhaust by 30%, but the required time to reach the top speed

Fresh Verbal Question From GMAT Club Tests'. Written by  sayantanc2k

Bunuel · Accepted Answer

GMAT Club Tests' Official Explanation:

A. Ideally the verb should be followed by the object, if possible. Here inserting the adverbial phrase “by 30%” between the verb “reduces” and the object “the harmful gases in the exhaust”. Is awkward. The ideal construction is “reduces the harmful in the exhaust gases by 30%”.

“Required time of reaching” is not idiomatic. Correct usage is “required time to reach”.

B. Parallelism error in the construction “not only X, but also Y”. Here, X = “reduces”, a verb, but Y = “the required time”, a noun phrase.

C. Parallelism error in the construction “not only X, but also Y”. Here, X = “reduces the harmful gases”, an active voice, but Y = “the required time is reduced”, a passive construction.

The first element X along with the main subject is grammatically alright - “Introducing a catalytic converter reduces the harmful gases…..” - but the second element Y along with the main subject is grammatically wrong - “Introducing a catalytic converter the required time to reach the top speed is reduced.”

Ideally the verb should be followed by the object. “Reduces” is the verb and its object is “the harmful gases in the exhaust”. The object is composed of “the harmful gases”, a noun phrase and “in the exhaust”, its “prepositional phrase modifier. Inserting a verb modifier “by 30%” between the noun phrase (“the harmful gases”) and its phrase modifier (“in the exhaust”) is awkward.

D. CORRECT.  Parallelism is maintained in the construction “not just X, but also Y”. Here X = “the harmful gases”, a noun phrase and Y = “the required time”, another noun phrase.

E. The meaning is distorted, because instead of the idiom “not only/just X, but also Y”, the idiom “not X, but Y” is used. This sentence wrongly indicates that introducing a catalytic converter does not reduce the harmful gases in the exhaust by 30%.

PyjamaScientist · Answer

(D) in my opinion. I took 01:19.

It tests Not X But also Y construction. Only D holds.

Posted from my mobile device

kungfury42 · Answer

Isn't "not only X but also Y" also a correct construction thereby making A right?

PyjamaScientist · Answer

Hi  kungfury42 ,
You are absolutely right about "not only X but also Y" construction. It indeed is a correct construction. But, there is another issue with (A), " required time  of reaching  the top speed ", it should rather be " required time   to reach   the top speed ". That's what (C) has in its sentence. The prepositional phrase " of reaching " is inferior to " to reach ". Thus,  (C)  is much more precise and correct.

kungfury42 · Answer

This makes a lot of sense, thank you for the help buddy, much appreciated.

sayantanc2k · Answer

Good catch! Option A maintains parallelism, but uses a wrong idiom.

For many SC questions, it may be useful to first identify the issues tested and then keep eliminating the choices by examining whether any of those issues has been violated - for example: issue 1: idiom, issue 2: parallelsim. Option A eliminated because of issue 1, option B because of issue 2 etc.

TarunKumar1234 · Answer

Introducing a catalytic converter not only reduces by 30% the harmful gases in the exhaust, but also reduces the required time of reaching the top speed.

A. not only reduces by 30% the harmful gases in the exhaust, but also reduces the required time of reaching the top speed -> We can say, not only x and but also y structure is followed, in which x and y seems parallel. But, "of reaching" is incorrect and we can have a better version if we say "the harmful gases in the exhaust by 30%". Incorrect.

B. not only reduces the harmful gases in the exhaust by 30%, but also the required time to reach the top speed -> "reduces" and "required" are not parallel. Incorrect.

C. not only reduces the harmful gases by 30% in the exhaust, but the required time to reach the top speed is also reduced -> "not only x" is correct structure. Further, "but" is used as coordinating conjunction and it is also correct. If we look closely, we can see X, reduces the harmful gases by 30% in the exhaust, is active voice but Y, the required time to reach the top speed is also reduced, is passive. Y could have been rephrased. I am keeping option C as of now and may drop, if I get a better one.

D. reduces not just the harmful gases in the exhaust by 30%, but also the required time to reach the top speed -> "not just harmful gases..." , "but also the required time..." we can see parallelism, X and Y have noun phases too. It makes Option D better than C. Let's keep Option D.

E. reduces not the harmful gases in the exhaust by 30%, but the required time to reach the top speed -> Missing "only" created meaning distortion. Incorrect.

So, I think D.

Masri · Answer

Answer is D, I think. Not only// But also structure is maintained in D.

Was between A and D, Option A uses "of" instead of "to" and also the meaning of "reduces by 30% the harmful gases" gives the feeling that it could also be "reduces by 70% or 100% the harmful gases", which is not the intended meaning.

brianmontanaweb · Answer

A - "also reduces" is repetitive 
B - Don't see errors, a few people mentioned "required" as not being parallel but it's an adjective, the verb is "also", which is a placeholder for reduces
C - Incorrect idiom use "not only" "but the"
D - Incorrect idiom use "but also" without "not only"
E - Awkward and parallelism issues

PyjamaScientist · Answer

(B) is wrong for parallelism. Even if you say that  not only   X    but also   Y  is the correct idiom,  X  and  Y  still have to be parallel for it to be correct. But, they are not parallel. " not only   reduces   the harmful gases " is not parallel to " but also   the required time ",  reduces  is missing in the second part.

To avoid making such errors in future, you need to keep the following things in mind: 
  ' Not Only   X    But Also   Y ' need not always exist together. But what MUST always occur is  X  SHOULD BE PARALLEL TO  Y .
Word combinations such as “not only … but also” should be followed by an element of the same grammatical type. 
Examples: Correct: “I have called  not only   to thank her   but also   to tell her  about the next meeting.”
All the following forms are correct depending on usage: 
 not only ...,  but also .... 
 not only ..,  but  (also)... ( also optional). 
 not only ..., (but)  also ... (but optional). 
 not only ... (but) (also).. (both but and also optional)
not only (optional) ..  but also

VerbalBot · Answer

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Introducing a catalytic converter not only reduces by 30% the harmful

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Introducing a catalytic converter not only reduces by 30% the harmful

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