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GMAT Sentence Correction: Do You Got What It Takes? – Explanation

Welcome back! Before we get started, take a moment to review Monday’s Sentence Correction question.
 

Question

In the middle of the 19th century, mathematician turned computer scientist Ada Lovelace aided Charles Babbage by developing the first computer algorithm, a breakthrough that ushered in the computer age, leading to machines capable of executing functions far more rapidly than could any possible human and resulting in every subsequent development in the field, from the development of the very first personal computer nearly a century later to the programs that today sequence genomes.

(A) mathematician turned computer scientist Ada Lovelace aided Charles Babbage by developing the first computer algorithm, a breakthrough that ushered in

(B) Ada Lovelace, mathematician and computer scientist, aided Charles Babbage by developing the first computer algorithm, ushering in

(C) Ada Lovelace, who was a mathematician turned computer scientist, aided Charles Babbage in developing the first computer algorithm, which ushered in

(D) the mathematician turned computer scientist, Ada Lovelace, aided Charles Babbage in developing the first computer algorithm; she ushered in

(E) Ada Lovelace, the mathematician turned computer scientist, aided Charles Babbage by developing the first computer algorithm, ushering in
 

Answer and Explanation

Two possible pitfalls:

Pitfall #1

This is a tricky question. Be careful not to get a case of “eliminitis” and unthinkingly get rid of (A) and (D). Sure, it’s tempting given that we automatically think that Ada Lovelace should immediately follow the comma. However, it is fine to have an adjective immediately following the comma as long as that adjective is modifying Ada Lovelace.

Pitfall #2

If you read the entire sentence, you’ll notice the two participles “leading” and “resulting”. Almost, reflexively our brain screams parallelism and we eliminate every answer choice that doesn’t have “ushering”. However, “leading” and “resulting” are not the second and third members of a list of three participles. Rather, we have a phrase with the past tense of ushered that is modified by the two participles “leading” and “resulting”. In other words, these two participles describe a noun in the preceding clause.

The original answer has “breakthrough” as this noun. The other answer choices change it so suddenly either Ada Lovelace is leading to every subsequent development in computers (weird) or the algorithm itself is leading to machines capable of executing functions (not as weird). For this reason, (B), (C), (D), and (E) can all be eliminated.

(A) provides the correct noun “breakthrough”, which serves as a summative modifier describing the work of Ada Lovelace. Only (A) does this.

Answer: (A)

Short cut

3:2 Split: “aided in Verb-ing” vs. “aided by Verb-ing”.

This helps us eliminate (B) and (E) right away, making this tough question a little bit easier.

 

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4 Responses to GMAT Sentence Correction: Do You Got What It Takes? – Explanation

  1. Isha January 11, 2016 at 8:22 pm #

    Hi Chris,

    do the words “aided in” and “aided by” result in a subtle meaning difference?

    Ada Lovelace aided Charles Babbage by…- here does the sentence mean that Ada was the sole person who worked on developing the algorithm

    Ada Lovelace aided Charles Babbage in…- here does the sentence mean that Ada was assisted Charles and both of them worked on developing the algorithm

    The correct answer does not clear this difference for me.

    Also I searched NY Times with this search query on google – site:nytimes.com “aided by”. it gave me 30K+ results.

    Is aided by is always wrong ?
    Does aided in and aided by differ in the meaning they imply?

  2. Andy Mann February 13, 2015 at 12:51 pm #

    Hi Chris,

    Thanks for your post. I previously read on magoosh that the correct idiom is “Aided in” but here answer A is using “Aided by”. Please clarify. The post I am referring to is below:

    http://magoosh.com/gmat/2013/gmat-prepositions-and-idioms-in-and-by/

    Thanks,
    Andy

    • Chris Lele
      Chris Lele February 17, 2015 at 4:09 pm #

      Oh gosh–that is flat out wrong. That should be “aided in developing”. Sorry for the confusion, and thanks for catching that. I realize, too, the “aid in” and “aid by” split should also be mentioned in the explanations. I’ll take care of that now :).

      Thanks again!

      • Deepak October 31, 2015 at 1:16 am #

        Hey, I just solved this problem and noticed that the question underlined phrase does not match the choice A !


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