By devising an instrument made from a rod, wire, and lead balls, and

The topics tested here are Modifiers, Meaning and Parallelism

(A) and (B) erroneously modify "Henry Cavendish’s apparatus" instead of "Henry Cavendish"

(C) This has a meaning error, the "and" before 1797-1798 changes the meaning

(D) This has a parallelism error, "Devised" vs "Employment"

Hence (E) is the correct answer.

mikemcgarry
MartyTargetTestPrep
AjiteshArun
GMATNinja

I need some help finding the right reason to eliminate Option C. I understand why Option E is correct however my reason for elimination Option C was not the same as mentioned in the explanations posted on this thread.

(C) Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and in 1797???1798 was able

The way I read this sentence is:

Independent Clause 1: Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements,

and - Coordinating conjunction
,+ and is used to join 2 independent clauses.

Clause 2: in 1797-1798 was able to arrive at an astonishingly accurate figure for the weight of the earth

There is no subject here for clause 2. And hence this cannot stand as an independent clause.
So, my reason for eliminating Option C was, +and is used to connect an independent and a dependent clause. That's wrong.

Whereas, the explanations say that there is a meaning issue. I understand that there is a meaning issue. But want to know whether C is grammatically correct? And if yes, how? What are the issues in my explanation?

Thank you
Sonal

Many people consider it acceptable to add place a comma before an "and" that connects an additional predicate to a sentence because commas can be added to sentences with some discretion.

Consider this example:

John sailed over the horizon one fine morning, and never came back.

In that example, the comma before "and" is not necessary, but it serves the purpose of creating a pause and, thus, emplasizing the second predicate "and never came back."

So, even though "and never came back" is not an independent clause, many people would consider that sentence correct.

Thus, such a comma placement does not render a sentence incorrect, at least not in the eyes of many people, and therefore, eliminating an SC choice because of the presence of such a comma is not the way to go.

In fact, in GMAT SC, the presence or lack of a comma is only very rarely a reason to or part of a reason to eliminate a choice.

So, the safest way to eliminate choice (C) of this question is to notice the flaw in the meaning conveyed by that version.

mikemcgarry Sir could you please elaborate how and what should we pick up for challenging reading daily ? That would help all a lot struggling with getting better with SC

Process:

1. Scan the answers - identify the potential issue: modification (Mod.) + parallelism (//m) + tense (1798)
2. Write down the 5 lines
3. Write down SVO
4. Read the sentence
5. Identify the SVO: S-HC, V- devised and employed, O- tool to measure
6. Identify the //m issue: devised and employed or devising and employing
7. POE . . . you must have a reason why each option is wrong - NOT sounding right is not a good reason!!!

A. By devising and employing, the date . . . incorrect - implies the date did the action. Eliminate!
B. //m: (tick) , and - modifier? + passive voice - not great but keep
C. //m: (tick), SVO (tick) but ito of meaning - suggests he devised the thing some time earlier and only later in 1797 was able to use it - not sure but keep
D. //m: having devised and employment - incorrect. Eliminate!
E. //m: devising and employing (tick), SVO (tick), timeline (tick)
8. Now check for //m with the fixed portion of the sentence: was able in xxxx-xxx to (tick)
9. Compare with B &C: E>B, no passive voice. E>C gets the meaning/intention right.

Answer: E

Would appreciate feedback on my approach and thinking please

I have been wondering about the intended meaning of a sentence.

Given choices C and E, both are grammatically correct, I am not sure what judgement to use to pick between the two choices. They both make sense to me.

How do people suppose to pick between the choices ?

First, let's consider the (C) version.

Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and in 1797–1798 was able to arrive at an astonishingly accurate figure for the weight of the earth.

Notice that this version first simply lists two things that Henry Cavendish did - it lists that he devised an instrument and employed precise measurements - and it also says that he was able to arrive at a figure. As a result, the three things this version says are not connected. Did he use the instrument to arrive at the figure? Did the measurements have something to do with the instrument? The sentence does not connect these actions. Rather the sentence says three sort of random things about Henry Cavendish for no clear reason.

Now, let's consider the (E) version.

By devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements, Henry Cavendish was able in 1797–1798 to arrive at an astonishingly accurate figure for the weight of the earth.

Notice how, unlike the (C) version, this version clearly connects Henry Cavendish's actions. It conveys that he was able to arrive at the figure by devising the instrument and employing precise measurements. So, this version makes clear why the three facts about Henry Cavendish are mentioned and conveys a meaning that makes sense.

Mary's explanation is solid.

I would also add that C is, arguably, not grammatically correct.

b]Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and in 1797–1798 was able...[/b]

We have some parallelism happening here (and a moment of parallelism within parallelism, when listing what the instrument was made out of). But at the highest level we're listing what Cavanedish did:

Henry Cavendish DEVISED [a thing], and EMPLOYED [some things], and WAS ABLE TO [do a thing].

So the structure is: Henry Cavendish VERBED, and VERBED, and VERBED...

Items in parallel structure typically need only ONE conjunction (the exception would be something like "X AND Y AS WELL AS Z."

But you should not include multiple 'ands' for the same list in parallel structure.

Hi MartyTargetTestPrep,

Why isn't Option (C) out for incorrect parallelism?

Option (C) says " Henry Canvendish (i) devised.... and (ii) employed...."

Where does the second "and" logically fit in here?

Thanks.

-Aum

Here's the (C) version.

Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and in 1797–1798 was able to arrive at an astonishingly accurate figure for the weight of the earth.

We see three "and"s in the (C) version.

The first "and" connects the three-item list "a rod, wire, and lead balls."

The second "and" connects the two-item list "devised ... and employed."

The third "and" connects a two item list "devised ... and employed ..., and ... was able."

We can treat "devised ... and employed" as the first item of this last list. That item is a nested list of ACTIONS.

We can treat "was able" as the second item of of this last list. That item names as STATE OF BEING.

So, this last list uses the third "and" to connect the actions item of the list with the state of being item of the list, and the comma that precedes the third "and" is fine to use to indicate the split between these two parts of the third list.

By devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements, in 1797–1798 Henry Cavendish’s apparatus enabled him to arrive at an astonishingly accurate figure for the weight of the earth.

(A) By devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements, in 1797–1798 Henry Cavendish’s apparatus enabled him - The Pronoun cannot refer back to possessive form of the noun.

(B) In 1797–1798, by devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements, Henry Cavendish’s apparatus enabled him - The Pronoun cannot refer back to possessive form of the noun.

(C) Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and in 1797–1798 was able - This sentence works in parallelism in the first part 'HC devised and employed measurement' but then the third element 'was able to arrive' is also made parallel which shouldn't be so as the emphasis is on the third element. By doing A and B the third was achieved. But because this option is still better than previous grammar errors we'll keep it at the table and look at others

(D) Having devised an instrument from a rod, wire, and lead balls, and employment of uncommonly precise measurements, Henry Cavendish in 1797–1798 was able - Parallelism error as 'having devised' not parallel to 'employment'

(E) By devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements, Henry Cavendish was able in 1797–1798 - By devising, employing HC was able to do this. This fixes the superficial parallelism in C. SELECT E

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and by doing so he was able to arrive at an astonishingly accurate figure for the weight of the earth, in 1797–1798.

Concepts tested here: Meaning + Modifiers + Parallelism + Awkwardness/Redundancy

• In a “phrase + comma + noun” construction, the phrase must correctly modify the noun; this is one of the most frequently tested concepts on GMAT sentence correction.

A: This answer choice incorrectly uses "By devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements" to modify "Henry Cavendish’s apparatus", illogically conveying that Henry Cavendish’s apparatus devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements; the intended meaning is that Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements; remember, in a “phrase + comma + noun” construction, the phrase must correctly modify the noun.

B: This answer choice incorrectly uses "by devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements" to modify "Henry Cavendish’s apparatus", illogically conveying that Henry Cavendish’s apparatus devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements; the intended meaning is that Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements; remember, in a “phrase + comma + noun” construction, the phrase must correctly modify the noun.

C: This answer choice alters the meaning of the sentence through the phrase "and in 1797–1798 was able"; the construction of this phrase incorrectly implies that Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and as a separate action he was able to arrive at an astonishingly accurate figure for the weight of the earth, in 1797–1798; the intended meaning is that Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and employed uncommonly precise measurements, and by doing so he was able to arrive at an astonishingly accurate figure for the weight of the earth, in 1797–1798.

D: This answer choice alters the meaning of the sentence through the phrase "and employment"; the parallelism between "an instrument" and "employment" illogically implies that Henry Cavendish devised an instrument made from a rod, wire, and lead balls and devised a way to employ uncommonly precise measurements; the intended meaning is that Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and he employed uncommonly precise measurements. Further, Option D uses the needlessly indirect and passive construction "Having devised", leading to awkwardness.

E: Correct. This answer correctly choice uses the phrase "By devising an instrument made from a rod, wire, and lead balls, and employing uncommonly precise measurements" to modify "Henry Cavendish", conveying the intended meaning - that Henry Cavendish devised an instrument made from a rod, wire, and lead balls, and he employed uncommonly precise measurements, and by doing so he was able to arrive at an astonishingly accurate figure for the weight of the earth, in 1797–1798. Further, Option E is free of any awkwardness or redundancy.

Hence, E is the best answer choice.

To understand the concept of "Phrase Comma Subject" and "Subject Comma Phrase" on GMAT, you may want to watch the following video (~1 minute):



All the best!
Experts' Global Team

MartyTargetTestPrep Option E entire eliminates 'apparatus'. Is that permissible? It surely is the most sensible of all options, and my only apprehension is that the original sentence says the apparatus enabled Cavendish to do XYZ, while Option E does not mention the apparatus or the enablement. TIA!

A sentence version in an SC question is correct not because it somehow matches the (A) version but because it is grammatically correct and effectively conveys a logical meaning.

Sometimes, when we're having difficulty determining which version conveys the most logical meaning, it can be helpful to consider what meaning the sentence seems meant to convey, but we can get clues regarding that meaning from any version of the sentence, not just from the (A) version. The (A) version isn't special.

Accordingly, the correct version can use a word that does not appear in the (A) version or leave out a word that does appear in the (A) version.

In the case of the correct answer to this question, there's no need for the word "apparatus" in the (E) version. After all, the "instrument" described by (E) is the apparatus. So, it's fine that "apparatus" doesn't appear in (E). The apparatus is still mentioned by the sentence even though it doesn't use that word.

Meanwhile, notice that the enablement is not missing from (E). After all, the (E) version says, "Henry Cavendish was able." So, the (E) version still communicates that Henry Cavendish became able through devising an instrument, or apparatus. It just says that in a different and more effective way than the (A) version.

Hello guhahaha,

Although you have gotten the response to your question, your doubt is so interesting that I could not resist answering. Let me present my two cents here.

It is common to find words and/or expressions omitted or added to the correct answer choice. The practice is not very frequent, but it exists. Omissions and additions happen to enhance the precision of the sentence in conveying the intended logical meaning of the sentence. Choice E already states that Cavendish devised an instrument that enabled him to do something. It is really not necessary to mention "apparatus" again. Also, the omission of the word does not interfere with the clarity and precision of the sentence in conveying the meaning. Therefore, such omissions are fine.

Let me present to you an official sentence in which a new expression is added in the correct answer choice - the expression that does not appear in the original sentence.


A star will compress itself into a white dwarf, a neutron star, or a black hole after it passes through a red giant stage, depending on mass.


(A) A star will compress itself into a white dwarf, a neutron star, or a black hole after it passes through a red giant stage, depending on mass.

(B) After passing through a red giant stage, depending on its mass, a star will compress itself into a white dwarf, a neutron star, or a black hole.

(C) After passing through a red giant stage, a star’s mass will determine if it compresses itself into a white dwarf, a neutron star, or a black hole.

(D) Mass determines whether a star, after passing through the red giant stage, will compress itself into a white dwarf, a neutron star, or a black hole.

(E) The mass of a star, after passing through the red giant stage, will determine whether it compresses itself into a white dwarf, a neutron star, or a black hole.


The correct answer choice for this official question uses an expression not present in the original sentence. The principle, however, again is the same. The addition of this expression adds clarity to the meaning conveyed by the sentence.


Hope this helps.
Thanks.
Shraddha

@crackgmatverbal
Would "Henry Cavendish in 1797-1798 was able" be incorrect? I see that Choice E has the order slightly switched: "Henry Cavendish was able in 1797-1798".

Thank you!

SC# 1

^^ The correct choice is

The following questions is also from official one.
https://gmatclub.com/forum/by-providing ... ml#p677177

SC# 2

^^ The correct choice is
Hi RonTargetTestPrep, MartyTargetTestPrep, GMATNinja, AjiteshArun, sayantanc2k
According to SC# 1, why did we not pick choice D in SC# 2? Can you clarify experts, please? This questions just make me crazy!