In a recent wave engine study, simulations of a pulsejet, a related

Question

In a recent wave engine study, simulations of a pulsejet, a related device  that employs deflagrations rather than detonations, was  also performed.

A. that employs deflagrations rather than detonations, was

B. employing deflagrations rather than detonations, were

C. employed to deflagrate rather than detonating, were

D. the employment of which entails deflagration rather than detonation, were

E. that employs deflagrating rather than detonation, were

ATC93 · Answer

I am confused on the rules surrounding this problem. Were is plural. And was is singular.

But now that I think about it I suppose “were” is appropriate for the plural simulations.

My only other issue was decided between “employs” or “employing” and why the later is the correct form.

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happypuppy · Answer

Question Stem: In a recent wave engine study, simulations of a pulsejet, a related device that employs deflagrations rather than detonations, was also performed.

Error: Here, stem talks about `simulations` and should be `were` performed as plural.

A. that employs deflagrations rather than detonations, was
- Was is wrong

B. employing deflagrations rather than detonations, were
- Correct. `Were` is used, and `deflagrations and detonations` is parallel.

C. employed to deflagrate rather than detonating, were
- Wrong. `deflagrate and detonating` is not parallel.

D. the employment of which entails deflagration rather than detonation, were
- Wrong. `employment of which entails` is wordy and unnecessary

E. that employs deflagrating rather than detonation, were
- Wrong. `deflagrating and detonation` is not parallel.

TBT · Answer

E. that employs deflagrating rather than detonation, were

If in E it was "that employs deflagrations rather than detonations, were" , would it be correct?

DmitryFarberMPrep · Answer

TBT

It would work grammatically. Whether there's an important meaning difference between the singular (describing a process or general principle) and the plural (describing individual events) is a question for an aerospace engineer, but the GMAT wouldn't expect us to know enough to rule out one version or the other.

Bunuel · Answer

OFFICIAL EXPLANATION

In a recent wave engine study, simulations of a pulsejet, a related device  that employs deflagrations rather than detonations, was  also performed.

A. that employs deflagrations rather than detonations, was

Incorrect.

This answer choice is grammatically incorrect. The plural subject  simulations  does not agree with the singular verb  was .

What helps us identify this question as a Subject Verb Agreement question and identify the mistake is the following Stop Sign:

A long complex subject / a long distance between the subject and the verb

B. employing deflagrations rather than detonations, were

This answer choice corrects the original Subject Verb Agreement mistake by changing the singular verb  was  to the plural verb  were . In addition, it correctly uses the construction A rather than B. A and B parallel each other as they are both nouns.

C. employed to deflagrate rather than detonating, were

Not quite.

Although this answer choice corrects the original Subject Verb Agreement, mistake it is still grammatically incorrect. The construction A rather than B requires that A and B belong to the same part of speech. If A and B are unconjugated verbs, they should be of the same type. In this answer choice  to deflagrate  is a to+verb whereas  detonating  is a verb+ing.

What helps us identify this question as a Parallelism question as well as identify the mistake is the following Stop Sign:

A rather than B

D. the employment of which entails deflagration rather than detonation, were

Not exactly

Although this answer choice corrects the original mistake, it is stylistically flawed. The five-word phrase  the employment of which entails  is wordy. Look for an answer choice that is both grammatically correct and concise.

E. that employs deflagrating rather than detonation, were

Not really.

This answer choice corrects the original Subject Verb Agreement mistake but it is still grammatically incorrect. The construction  A rather than B  requires that A and B belong to the same part of speech. In this answer choice, A is an unconjugated verb ( deflagrating ) whereas B is a noun ( detonation ).

What helps us identify this question as a Parallelism question as well as identify the mistake is the following Stop Sign:

A rather than B

sonalirai · Answer

Why option B is correct? Don't we need a form of verb to be with employing?

VerbalBot · Answer

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In a recent wave engine study, simulations of a pulsejet, a related

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In a recent wave engine study, simulations of a pulsejet, a related

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