Many of today’s mathematicians use computers to test cases that are ei

Question

Many of today’s mathematicians use computers to test cases that  are either too time-consuming or involve too many variables to test manually, allowing the exploration of  theoretical issues that were impossible to test a generation ago

(A) are either too time-consuming or involve too many variables to test manually, allowing the exploration of

(B) either take too much time or involve too many variables to be tested manually; allowing the mathematicians to explore

(C) would either take too much time or involve too many variables to test manually, allowing them to explore

(D) would either be too time-consuming or would involve too many variables to test manually; this capability allows the mathematicians to explore

(E) take too much time or variables to test manually; this capability allows the mathematicians to explore

HansJK · Answer

If after the semi-colon in B, it would have read: "the computers allow the mathematicians to explore theoretical issues that were impossible to test a generation ago," would "the mathematicians" be the indirect object and "theoretical issues" be the direct object.

I struggle with identifying the object of a sentence, often confusing it for the subject.

Would really appreciate some help:)

I struggle with identifying the object of a sentence, often confusing it for the subject.

Would really appreciate some help:)

AndrewN · Answer

Hello,  HansJK . Yes, you would have it just right if the sentence were written as you proposed. Since you could replace  the mathematicians  with  them  (not  they ), you know you are dealing with an indirect object, and  theoretical issues  tells you  what  is being explored, and that means you have a direct object. As for your self-identified struggles, I cannot think of a time in my SC practice in which I felt I had to identify an object, direct or indirect, to know which continuation to favor. It is far more important to be able to identify the subject of a sentence, whether that be a gerund, an infinitive phrase, or a more straightforward person or thing.

I hope that helps. Good luck with your studies.

- Andrew

Manojdewani · Answer

1. in option C, does 'them' refers to computers or mathematicians?
2. How do we know that we need to use 'would' instead of plan sentence as in the case of Option B which omits Helping verb altogether?

svasan05 · Answer

Hi Manoj

Here are my two cents on this topic:

1) "them" in option (C) could theoretically refer to either computers or mathematicians. However, I prefer to only eliminate an answer option for having an ambiguous antecedent if we have another answer option without such a problem and any other errors. In this case, all other options have obvious errors so we have to live with an ambiguous antecedent.

2) "would" is used when expressing a hypothetical ie; the event has not happened and may not happen in the future as well. You could choose to go without the helping verb as in (B), but that subtly modifies the meaning of the sentence. Let us look at the sentence with option (B) plugged in:

Many of today’s mathematicians use computers to test cases that  either take too much time or involve too many variables to be tested manually; allowing the mathematicians to explore  theoretical issues that were impossible to test a generation ago.

This gives a subtly different meaning by implying that "take too much time" and "involve too many variables" are a general truth (since present tense is used without "would") ie; it has been done or is being done manually and these problems are being faced. Ignoring other errors, while this in itself is not wrong grammatically or logically (since the original sentence also appears to imply this), there are other errors in (B) which have been elaborated in other posts which makes the option incorrect.

Hope this helps.

BLTN · Answer

MartyTargetTestPrep

Dear Marty,
could you elucidate, besides countable & uncountable issue, is the pronoun "this" properly utilized? Can it refer to "using computers" ?

(E) take too much time or variables to test manually; this capability allows the mathematicians to explore

MartyTargetTestPrep · Answer

In this sentence "this" is used as a demonstrative adjective. As a demonstrative adjective, "this" points out a particular capability, "this capability."

There is a meaning issue, in that what precedes "this capability" in the sentence does not mention anything that would logically be described as a capability. So, "this capability" has nothing to which to refer.

Also, notice that "allows the mathematicians to explore ... issues that were impossible to test" doesn't really make sense.

The idea that one would "test" an issue that one is exploring isn't logical.

HansJK · Answer

In C, is not the pronoun "them" a bit unclear? Could it not be referencing "computers" as well?

EducationAisle · Answer

Agreed. However, pronoun  ambiguity , in general, should not be a reason to eliminate an answer choice.

Sajal12 · Answer

Hi experts,

Could you shed some light on the usage of would? I have read at multiple places that "would" is always used whe you want to tell future in past tense. However, the sentence is in present tense, then how would is correct?

raphael95959 · Answer

The option  D  is majorly ruled out because of issue with parallelism. So if the option  D  is changed to:

would either be too time-consuming or involve too many variables to test manually; this capability allows the mathematicians to explore

OR

either would be too time-consuming or would involve too many variables to test manually; this capability allows the mathematicians to explore

Are these options correct ? If yes, then can they be chosen over  C

Namangupta1997 · Answer

Hi  AndrewN

I eliminated option C as I thought the pronoun "them" is ambiguous. I am trying to understand how it unambiguously refers back to mathematicians. Is it because after the usage of "that" in the sentence, the entire "are either.....test manually" turns out to be nothing but an essential modifier modifying "cases" , rendering the "mathematicians" as the sole subject of the sentence and hence the unambiguous antecedent of the pronoun "them" ?

AndrewN · Answer

Hello,  Namangupta1997 . Pronoun ambiguity is not an egregious error in the way that a subject-verb agreement mismatch is. I agree that in answer choice (C),  them  could reasonably be interpreted as referring to either  mathematicians  or  computers . Test both cases in the context of the latter portion of the sentence:

1)   allowing  mathematicians  to explore  theoretical issues that were impossible to test a generation ago

2)   allowing  computers  to explore  theoretical issues that were impossible to test a generation ago

Either continuation is logical, and even  a generation  could be thought to comment on a generation within the human lifespan or a bygone generation of technology (e.g., 4G phones). But the important consideration is whether, however you choose to interpret the pronoun, you end up with a sentence that makes sense. Here, the answer is yes, so there is no compelling reason to drop option (C) from contention.

Whenever you come across pronoun ambiguity, you may want to mark it as a doubt and check other answer choices to see whether they address the issue, but do not blind yourself to errors or problems in other answer choices simply because you are clinging steadfastly to a doubt. The best answer is the safest option, not necessarily the best sentence that could be strung together to express the same thought.

Thank you for thinking to ask.

- Andrew

Namangupta1997 · Answer

Hi  AndrewN

That makes a lot of sense. Thanks for an in-depth analysis.

Just one follow up question : As we can see that in this case, if we replace "them" by the possible antecedents, the sentence still makes logical sense. No reason to drop C based on pronoun ambiguity. In another case, after replacing the antecedents and analyzing the meaning of the sentence, suppose we actually find atleast 1 ,out many possible antecedents , that does not fit the logical implication of the sentence. In that case, would we have sufficient information to drop that particular option based solely on pronoun ambiguity ?

AndrewN · Answer

To be direct, I would not use pronoun ambiguity as the sole basis for eliminating an answer choice. See  this post  by  GMATNinja , as well as the OG question above it, for another take on the issue. All other things being equal, if I saw two answer choices, one of which incorporated an ambiguous pronoun while the other did not, I would select the clearer option. Why? Because, going back to my earlier post, it would be the safer bet, and chasing could-be-true iterations of a sentence will get you into trouble in SC.

Thank you for following up.

- Andrew

aumd568 · Answer

GMATNinja   AndrewN   MartyTargetTestPrep

I totally missed the semicolon in my first attempt and spent quite some time between Option (B) and Option (C)

Ended up eliminating Option (B) since " to be tested manually " did not sound great....especially with " take too much time to be tested manually "

Was it a valid elimination?

-Aum

AndrewN · Answer

Hello, Aum. I think everyone would agree that going by your ear may not prove to be a sound strategy. A lot of terrible-sounding sentences end up being correct, while streamlined versions of a sentence can, at times, be too concise and miss some of the vital meaning that lengthier iterations of the sentence seem to capture. Here, between  to be tested manually  in option (B) and  to test manually  in option (C), the latter is more direct, but I would not use this consideration to eliminate (B). The semicolon, on the other hand, is a glaring error in that option, and you always want to look for easy targets.

If you are just getting into your studies, or perhaps getting into the thick of your preparation, you may want to steer clear of 700-level questions, especially those by third-party sources. There are far better official questions available, and your score will be made or broken on questions at the Medium level, so you want to do everything you can to get your skills in tip-top shape at that level before you progress to questions such as the one above.

Thank you for asking for my input.

- Andrew

mansianand1234 · Answer

''mathematicians use computers to test cases, allowing them to explore..''

does comma -ing tells us the how aspect of using computers? What aspect of verb does 'allowing' modify here?

ExpertsGlobal5 · Answer

Hello  mansianand1234 ,

We hope this finds you well.

To answer your query, Option C uses the "Comma + Present Participle ("verb+ing" - "allowing" in this sentence) construction; this construction typically conveys a cause-effect relationship; here, what it means is that mathematicians use computers to test cases that would either take too much time or involve too many variables to test manually, and   as a result  , they are able to explore theoretical issues that were impossible to test a generation ago.

To understand the concept of "Comma Plus Present Participle for Cause-Effect Relationship" on GMAT, you may want to watch the following video (~2 minutes):

https://www.youtube.com/watch?v=bE9Vm8zCIO0

All the best!
Experts' Global Team

austin316 · Answer

@e-GMAT

Can you pls help?

verb-ing modifiers should make sense with the subject, and the doer of the modified entity must be the same as the doer of the modifier. Here, "allowing them" does not seem to make sense with the subject as "them" refers to the subject itself.

Is my understanding correct?

Many of today’s mathematicians use computers to test cases that are ei

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Many of today’s mathematicians use computers to test cases that are ei

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