Logical Splits in GMAT Sentence Correction

1) Even-toed ungulates, including pigs, cattle, goats, and sheep, and odd-toed ungulates, such as horses and donkeys, account for all the mammals domesticated for agricultural purposes.

(A) including pigs, cattle, goats, and sheep, and odd-toed ungulates, such as horses and donkeys, account for

(B) including pigs, cattle, goats, and sheep, and odd-toed ungulates, including horses and donkeys, accounting for

(C) included among pigs, cattle, goats, and sheep, and odd-toed ungulates, such as horses and donkeys, account for

(D) included among pigs, cattle, goats, and sheep, and odd-toed ungulates, like horses and donkeys, are accounted for by

(E) like pigs, cattle, goats, and sheep, and odd-toed ungulates, like horses and donkeys, are accounted for by

2) While the marketing department projected robust sales throughout the summer, typically Allport Corporation’s biggest season, the drought in Midwestern states limited total revenue to only $300 million in the third quarter.

(A) typically Allport Corporation’s biggest season, the drought in Midwestern states limited total revenue to only

(B) Allport Corporation’s biggest typical season, the drought in Midwestern states limited only total revenue to

(C) which typically is Allport Corporation’s biggest season, the drought in Midwestern states only limited total revenue to

(D) which is typically Allport Corporation’s biggest season, the drought in Midwestern states limiting total revenue to only

(E) Allport Corporation’s biggest typical season, the drought in Midwestern states only limiting total revenue to

3) After establishing several lucrative deals in the Far East, the CEO of Brantford Industrial said that he wanted to encourage their expanding into promising overseas markets, the use of domestic suppliers for all materials besides oil products, and the acquisition of a more extensive distribution network.

(A) their expanding into promising overseas markets, the use of domestic suppliers for all materials besides

(B) their expansion into promising overseas markets, using domestic suppliers for all materials instead of

(C) its expansion into promising overseas markets, the use of domestic suppliers for all materials other than

(D) its expansion into promising overseas markets, using domestic suppliers for all materials other than

(E) its expanding into promising overseas markets, using domestic suppliers for all materials except

4) Daniel Bernoulli (1700 – 1782) derived the famous fluid equation named after him, to explain an airplane’s wing’s generation of lift, and made a discovery that led to an early method of measuring blood pressure.

(A) equation named after him, to explain an airplane’s wing’s generation of lift

(B) equation named after him, and this principle explains the lift of an airplane’s wing

(C) equation, named it after himself, explained how an airplane’s wing is generating lift

(D) equation named for him, giving an explanation of the generation of the lift of an airplane’s wing

(E) equation named for him, which explains how an airplane’s wing generates lift

 

Grammar and Logic

Folks often think of the GMAT Sentence Correction as a test of grammar.  Indeed, a great deal of grammar is tested, but folks typically underestimate the extent to which logic is tested on this question type.   The GMAT Sentence Correction is ultimately about logical and meaning, and grammar is only a means to express these.

If a student attempts to solve GMAT Sentence Correction questions purely by scouring the answers for grammar mistakes, that student will miss something.   In each question above, as on many official GMAC questions, there are wrong answers that are 100% grammatically correct but logically flawed.

Logical errors are subtle and can take many forms.  Some were already discussed in the post on Logical Predication.  For example, Parallelism is as much a logical structure as a grammatical structure, and it is perfectly possible to place in parallel elements that are grammatically compatible but logically incompatible.  For example:

lsigs_img1

The parallelism in that sentence is an example of False Parallelism: a construction that is grammatically correct but logically invalid.   My friend Kevin is an optimistic and enthusiastic guy, but he is a flesh-and-blood person, not the logical equivalent of abstract qualities.   Other logical errors include misplaced modifiers and mistakes for words referring to categories or other logical relationships.

 

Summary

If this brief article and any of the links provided insight into the questions above, you may want to give them a second look before reading the solutions below.  Here’s another question from inside Magoosh:

6) http://gmat.magoosh.com/questions/3219

If you have any insights you would like to share, or questions clarifying anything I have written here, please let us know in the comments section below.

lsigs_img2

Practice Problem Explanations

1) Split #1: first of all, the sentence needs a verb.  The word “account” must be in a full bonafide verb, to provide a main verb for the sentence.  Choice (B), in making this a participle, “accounting”, commits the famous missing verb mistake and so is incorrect.

Split #2: the GMAT does not approve of using the word “like” to list examples.  Choices (D) & (E) make this mistake, and are incorrect.

Split #3: A logic problem.  We may not be familiar with biological taxonomy, but the word set-up in the prompt suggests, for example, that “even-toed ungulates” is the larger category, and the individual animals (pigs, cattle, etc.) are exampled included in this larger category.   Choices (C) & (D) change the meaning: in using the passive participle “included among,” these choices suggest that the individual animals are the larger categories and that “even-toed ungulates” are some smaller classification within them.  This is factually incorrect, but even if you do not know the details of the scientific classifications, you can rely on the prompt to give you the correct logical relationships.   Choices (C) & (D) change the meaning, so they are incorrect.

Split #4: Another logic problem.  The idiom “to account for” means, roughly, to show where the numbers or elements of something come from.  The prompt says that these larger biological groups “account for” the relatively small group of mammals domesticated for agricultural purposes: this is correct.  Choices (D) & (E) reverse this relationship, suggesting that the relatively agricultural small group can provide the membership for the much larger biological group.  First of all, that is patently illogical, but even if you don’t fully understand this, recognize that, in changing the main verb from active passives, these two choices change the meaning from the one given in the prompt, and therefore are incorrect.

The only possible answer here is (A).

2) Split #1: the famous missing verb mistake.  The sentence begins with a subordinate clause starting with the word “while”, and that has a bonafide noun + verb structure, as it should, but we need a main subject and main verb for the sentence.  The “drought” is the main subject, and this needs a bonafide verb, “limited“, not just the participle, “limiting.”  Choices (D) & (E) are incorrect.

Split #2: the structure “summer, Allport Corporation’s biggest season” is correct: this is an appositive phrase.  The structure ” summer, which is Allport Corporation’s biggest season” is grammatically correct, but a bit wordier.

Split #3: in saying, “summer, typically Allport Corporation’s biggest season,” we are saying that a typical pattern is that, of the four seasons, summer is the most lucrative.  This is the meaning intended, the meaning given in the prompt.  Saying ” summer, Allport Corporation’s biggest typical season” implies that Allport has typical seasons and untypical seasons, and among the typical seasons, summer is the biggest: this changes the meaning to one that  makes far less sense, so this structure is wrong.  Choice (B) & (D) are wrong.

Split #4: the word “only.”  Exactly what do we want to limit with the word “only”?  Clearly, what is limited is “only $300 million” — presumably, Allport was expecting to earn more than this.   It makes no sense to put the word “only” before the verb “limited” or the direct object “total revenue”: the structure “only limited” implies that the drought could have done more to the total revenue beyond merely limiting it, and the structure “only total revenue” implies that something else was limited besides total revenue.  Both of those placements change the meaning from the one implied in the prompt to something nonsensical, so choice (B) & (C) & (E) are incorrect.

The only possible answer here is (A).

3) Split #1: pronoun problems.  The CEO is clearly talking about what he wants for Brantford Industrial.  Brantford Industrial is presumably a big company with lots of employees, but as a collective noun, it is singular, and must take the singular pronoun “it.” The plural pronoun “they” is incorrect, and choices (A) & (B) make this mistake.

Split #2: Parallelism, part one.  Clearly we have parallelism in this question, in the things that the CEO wanted to encourage.  The final element is “the acquisition”, so we expect other elements to have a parallel structure.  The first element should be “expansion”, not “expanding.”  Choices (A) & (E) make this mistake.

Split #3: Parallelism, part two.  The big question is: how many elements are in parallel.  It could be three “the expansion, … the use, … and the acquisition” or, the middle one could be the participial phrase “using,” modifying the first element.   Choices (C) & (D) are both 100% grammatically correct, and we have to decide purely on the basis of logic.

version (C): its expansion into promising overseas markets, the use of domestic suppliers for all materials other than oil products, and

version (D): its expansion into promising overseas markets, using domestic suppliers for all materials other than oil products, and

Version (C) implies that the CEO encouraged three different things,  and that the use of domestic suppliers is a different agenda item from the overseas expansion.  Version (D) implies that the CEO encouraged two different things,  and that he wants the first, overseas expansion, done by using only domestic suppliers.  There is something fishy about this second version: why would we want to do all business overseas with only domestic suppliers?  More importantly, these are two different meanings, and version (C) is faithful to the meaning given in the prompt.  Therefore, version (C) is the best answer.

4) Split #1: You don’t have to have tremendous outside knowledge for GMAT SC questions, but you do need to have the very basic knowledge that, for example, airplanes did not exist in the eighteenth century.  It may be true that the equation once derived by Bernoulli is now explaining how planes work, but Mr. Bernoulli himself had no experience of airplanes and therefore could not be trying to explain them.   Choices (A) & (C) directly imply this, and (D) may imply it as well.   Certainly (A) & (C) are out, and we are very suspicious of (D) as well.

Split #2: apparently the equation Mr. Bernoulli derived was named after him, Bernoulli’s Equation, but it changes the meaning to say that he was the one to name it after himself.  Choice (C) makes this mistake, in the false parallelism it creates.

Split #3: The double possessives in choice (A) is painfully awkward.  This is another problem with (A).

Split #4: both the verb “derived” and “made” are verbs in parallel that have Mr. Bernoulli as the subject.  We could have another verb with the same subject in parallel between them, but we can’t have a full independent clause between them.  Choice (B) makes that mistake.

Split #5: Choice (D) makes the information following “giving” as long and awkward and indirect as possible.  It gives a long string of nouns in preposition: “an explanation of the generation of the lift of an airplane’s wing.”  What’s being described is an action, but this choice does not use any active language in describing it.   While this choice is grammatically correct, rhetorically it is a disaster.  Choice (D) is incorrect.

The only possible answer is (E).

 

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  • Mike MᶜGarry

    Mike served as a GMAT Expert at Magoosh, helping create hundreds of lesson videos and practice questions to help guide GMAT students to success. He was also featured as "member of the month" for over two years at GMAT Club. Mike holds an A.B. in Physics (graduating magna cum laude) and an M.T.S. in Religions of the World, both from Harvard. Beyond standardized testing, Mike has over 20 years of both private and public high school teaching experience specializing in math and physics. In his free time, Mike likes smashing foosballs into orbit, and despite having no obvious cranial deficiency, he insists on rooting for the NY Mets. Learn more about the GMAT through Mike's Youtube video explanations and resources like What is a Good GMAT Score? and the GMAT Diagnostic Test.