Lacking information about energy use, people tend to overestimate the

Hello Everyone!

Let's tackle this question, one thing at a time, and narrow down our options quickly so we know how to answer questions like this when they pop up on the GMAT! To begin, let's take a quick look at the question and highlight any major differences between the options in orange:

Lacking information about energy use, people tend to overestimate the amount of energy used by equipment, such as lights, that are visible and must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.

(A) equipment, such as lights, that are visible and must be turned on and off and underestimate that
(B) equipment, such as lights, that are visible and must be turned on and off and underestimate it when
(C) equipment, such as lights, that is visible and must be turned on and off and underestimate it when
(D) visible equipment, such as lights, that must be turned on and off and underestimate that
(E) visible equipment, such as lights, that must be turned on and off and underestimate it when

After a quick glance over the options, we have a few key differences to focus on to help narrow down our choices:

1. equipment vs. visible equipment
2. that / that are visible / that is visible
3. that vs. it when

Let's start with #1 & #2 on our list because they both deal with the same grammar issue: concision/wordiness. The GMAT prefers concise, clear language whenever possible, so we need to determine which phrasing option is the clearest and most concise. The easiest way to do this is to take out the phrase "such as lights," since it's only there to trip us up:

equipment...that are visible = WRONG = This is both overly wordy AND a subject-verb agreement problem. Equipment is a singular word, so we can't use a plural verb "are."
equipment...that is visible = WRONG = While this option fixes the subject-verb agreement problem, it's still not the most concise option.
visible equipment = CORRECT = This conveys the same meaning as "equipment that is visible" in half as many words! This is our choice!

We can eliminate options A, B, & C because they are not concise and/or have subject-verb agreement problems.

Now that we have it narrowed down to only 2 options, let's tackle #3 on our list - that vs. it when - which is an issue of both pronouns & parallelism! To make potential problems easier to spot, let's add back in the non-underlined portions of the sentence.

(D) Lacking information about energy use, people tend to overestimate the amount of energy used by visible equipment, such as lights, that must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.

This is the CORRECT option because the pronoun "that" is clearly referring back to "the amount of energy." If you were to replace the word "that" with "the amount of energy," this would still make perfect sense!

Also, if we replace the pronoun with the phrase it's referring back to, the 2 actions are parallel:

overestimate the amount of energy used by visible equipment
underestimate the amount of energy used by unobtrusive equipment

(E) Lacking information about energy use, people tend to overestimate the amount of energy used by visible equipment, such as lights, that must be turned on and off and underestimate it when used by unobtrusive equipment, such as water heaters.

This is INCORRECT for a couple reasons. First, the pronoun "it" isn't clearly referring back to "the amount of energy" as clearly as in option D. Even if we replace the pronoun "it" with "the amount of energy," we also have a parallelism problem! There are 2 actions people are doing in this sentence:

overestimate the amount of energy used by visible equipment
underestimate the amount of energy used when by unobtrusive equipment

Since these two actions aren't written using parallel construction, we have to toss this one out!

There you have it - option D is the correct choice! By finding the splits among our 5 options, we were able to eliminate several incorrect choices quickly, leaving us more time to focus on the more nuanced grammar problems at hand!


Don't study for the GMAT. Train for it.

Official Explanation

Rhetorical construction; Agreement

This sentence, as worded, has a subject-verb agreement problem: the noun equipment, not lights, serves as the subject of the verb are; because equipment is singular, is should be used. Furthermore, the sentence would read more clearly if visible equipment were used rather than equipment . . . that [is] visible. This would create a less wordy sentence that has a more parallel structure, in which visible equipment is contrasted with unobtrusive equipment.

A. This version is flawed for the reasons given above.

B. This version has the same subject-verb agreement problem as in A. Furthermore, it is unclear what the referent of the pronoun it is here. Finally, this version, like A, is wordy, and its structure is not parallel.

C. This version correctly uses the singular verb is. However, as in choice B, the pronoun it has no clear referent. Finally, this version, like A and B, is wordy, and its structure is not parallel.

D. Correct. This version is free of subject-verb agreement errors and its structure is parallel.

E. Although this version is free of subject-verb agreement errors and appropriately uses a parallel structure, it retains the problem from choices B and C: the pronoun it has no clear referent.

The correct answer is D.

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 core meaning of this sentence is that people tend to overestimate the amount of energy used by visible equipment that must be turned on and off and underestimate the amount of energy used by unobtrusive equipment.

Concepts tested here: Subject-Verb Agreement + Meaning + Awkwardness/Redundancy

A: This answer choice incorrectly refers to the singular noun "equipment" with the plural verb "are". Further, Option A uses the needlessly wordy phrase "that are visible", leading to awkwardness and redundancy.

B: This answer choice incorrectly refers to the singular noun "equipment" with the plural verb "are". Further, Option B alters the meaning of the sentence through the phrase "underestimate it when"; the construction of this phrase illogically implies that people underestimate the amount of energy used by visible equipment at the time when the same amount is used by unobtrusive equipment; the intended meaning is that people tend to underestimate the amount of energy used by unobtrusive equipment. Additionally, Option B uses the needlessly wordy phrase "that are visible", leading to awkwardness and redundancy.

C: This answer choice alters the meaning of the sentence through the phrase "underestimate it when"; the construction of this phrase illogically implies that people underestimate the amount of energy used by visible equipment at the time when the same amount is used by unobtrusive equipment; the intended meaning is that people tend to underestimate the amount of energy used by unobtrusive equipment. Further, Option C uses the needlessly wordy phrase "that is visible", leading to awkwardness and redundancy.

D: Correct. This answer choice avoids the subject-verb disagreement seen in Options A and B, as it uses the phrase "visible equipment" rather than the phrase "that are visible", meaning no active verb is used to convey that the equipment is visible. Further, Option D uses the phrase "underestimate that used by unobtrusive equipment" - wherein "that" refers to "amount of energy" - conveying the intended meaning - that people tend to underestimate the amount of energy used by unobtrusive equipment. Additionally, Option D is free of awkwardness and redundancy.

E: Trap. This answer choice alters the meaning of the sentence through the phrase "underestimate it when"; the construction of this phrase illogically implies that people underestimate the amount of energy used by visible equipment at the time when the same amount is used by unobtrusive equipment; the intended meaning is that people tend to underestimate the amount of energy used by unobtrusive equipment.

Hence, D is the best answer choice.

All the best!
Experts' Global Team

Lacking information about energy use, people tend to overestimate the amount of energy used by equipment, such as lights, that are visible and must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.

(A) equipment, such as lights, that are visible and must be turned on and off and underestimate that

(B) equipment, such as lights, that are visible and must be turned on and off and underestimate it when

(C) equipment, such as lights, that is visible and must be turned on and off and underestimate it when

(D) visible equipment, such as lights, that must be turned on and off and underestimate that

(E) visible equipment, such as lights, that must be turned on and off and underestimate it when


The question is mainly based on Parallelism.

The sentence draws a comparison between two kinds of equipment. The sentence also contains a modifier that gives an example of each type of equipment - "such as lights", "such as water heaters".

The two types of equipment must have a similar form. We get our clue from the non-underlined portion of the sentence, which mentions “unobtrusive equipment".

Options A, B, and C contain the phrase “equipment, such as lights”.

Options D and E contain the phrase “visible equipment”.

Between the two phrases, “visible equipment” is parallel in structure to “unobtrusive equipment. So, we can rule out Options A, B, and C.

D and E are very similar in structure.
But E has the pronoun “it” and the adverb “when”, that affect the parallelism in the sentence.
“overestimate the amount of energy used by visible equipment, such as lights, that must be turned on and off and underestimate it when used by unobtrusive equipment, such as water heaters.”
So, E can be eliminated.

The appropriate structure of the sentence that maintains parallelism is in Option D:
“overestimate the amount of energy used by visible equipment, such as lights, that must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.”
As can be seen in the highlighted portions, the structure is almost identical except for the difference in words required by the meaning of the sentence. The pronoun 'that' refers to 'the amount of energy'.
Therefore, D is the most appropriate option.

Jayanthi Kumar.

I chose D for this answer choice.

First of all, "visible equipment" is more concise than saying "equipment that is visible." Now suppose that you couldn't tell which way is more concise: "equipment" is singular, so you can't say "that ARE" to refer to equipment. That would eliminate answer choices A and B.
Now, option C does say "that is", which is correct. However, the last part of this answer choice says "it when", which is wrong, so option C is out. "it" refers only to a noun. What this sentence wants to refer to is "the amount of energy", to which you can refer using "that." Looking at options D and E, only D does this job perfecty well.

It's parallel to say, "the amount of energy used" and "that used."

cheers

visible equipment and unobtrusive equipment - parallel. that D and E.

Between D and E....D is parallel

overestimate the amount of energy used by visible equipment.......and underestimate that [amount of energy] used by unobtrusive equipment.............

Lacking information about energy use, people tend to overestimate the amount of energy used by equipment, such as lights, that are visible and must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.

(A) equipment, such as lights, that are visible and must be turned on and off and underestimate that
(B) equipment, such as lights, that are visible and must be turned on and off and underestimate it when
(C) equipment, such as lights, that is visible and must be turned on and off and underestimate it when
(D) visible equipment, such as lights, that must be turned on and off and underestimate that - correct
(E) visible equipment, such as lights, that must be turned on and off and underestimate it when

I have following doubt in option D.

In option D - first "that" refers to "visible equipment" and second "that" refers to "the amount of energy".
How can the same "that" refer to two different entities in a sentence?

Hi RMD007, you ask a very good question.

The thing is that here, the first "that" is a completely different usage from the second "that".

The first "that" is used as a relative pronoun, while the second "that" is used as a demonstrative pronoun.

By the way, apart from these two usages, that also has a third usage: as a conjunction. All the three usages of "that" are quite frequently tested on GMAT.

p.s. Our book EducationAisle Sentence Correction Nirvana discusses the avatars of "that", their application and examples in significant detail. Have attached the corresponding section of the book, for your reference.

Lacking information about energy use, people tend to overestimate the amount of energy used by equipment, such as lights, that are visible and must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.

A. equipment, such as lights, that are visible and must be turned on and off and underestimate that -- 'equipment, such as lights, 'that are visible' is not parallel to 'unobtrusive' equipment.

B. equipment, such as lights, that are visible and must be turned on and off and underestimate it when -- same as in A

C. equipment, such as lights, that is visible and must be turned on and off and underestimate it when--- same as in A and B; 2. lights that is visible -- is an SV mistake.

D. visible equipment, such as lights, that must be turned on and off and underestimate that ---- 1. 'visible' and 'unobtrusive' - are parallel. 2. the relative pronoun 'that' correctly refers to the amount of energy -- correct choice.

E. visible equipment, such as lights, that must be turned on and off and underestimate it when -- 1. the antecedence of 'It' is un clear. It could refer to ' either equipment' (as a single equipment), or to the energy. 2. The adverb 'when' gives a wrong twist as if the under estimation occurs only when used by the equipment and not when they are idle. However, the idea here is a generalization about the equipment and not a comparison

Lacking information about energy use, people tend to overestimate the amount of energy used by equipment, such as lights, that are visible and must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.

A. equipment, such as lights, that are visible and must be turned on and off and underestimate that - SV error

B. equipment, such as lights, that are visible and must be turned on and off and underestimate it when -SV error

C. equipment, such as lights, that is visible and must be turned on and off and underestimate it when -1. it can refer to equipment. 2. Incorrect usage of when

D. visible equipment, such as lights, that must be turned on and off and underestimate that-CORRECT.Second that correctly refers to amount of energy

E. visible equipment, such as lights, that must be turned on and off and underestimate it when -1. it can refer to equipment. 2. Incorrect usage of when

If C did not had pronoun ambiguity "it"
would it be still correct?

Hello haardiksharma,

I will be glad to help you out with this one.

Even if the issue of pronoun it is resolved, Choice C will still remain incorrect for the usage of when.

See, the word when is used quite literally on GMAT SC. With the usage of this word, Choice C suggests that people underestimate the amount of energy when used by unobtrusive equipment. Otherwise they do not. Hence, usage of when makes Choice B, C, and E incorrect.


Hope this helps.
Thanks.
Shraddha

Hello Ashish EducationAisle

I have a related question, I understand in parallelism the sentence have to logical as well as grammatical.

(D) visible equipment, such as lights, that must be turned on and off and underestimate that

In the correct option the first "that" is acting as a modifier - modifying "visible equipment" and second "that" is acting as a pronoun.
Can be this be called parallel grammatically ?

I am finding it hard to explain my difficulty, but hope you can understand the question

AjiteshArun can you help too ?

If you try to get a hang of what the author wants to convey you will know that it's all about parallel structure and pronoun reference. Between A and D the former is the best fit as it is concise and clearly conveys what the author wants to.

Hi! Actually in both instances, that is used as a pronoun: relative pronoun in the first case and demonstrative pronoun in the second case.


There is no parallelism of that being tested in this question. The parallelism here is between overestimate and underestimate, both verbs (used as infinitives here).

Hi Gaurav, the answer is the latter by the way.

AjiteshArun GMATNinja

Even though I was able to identify option D as the correct answer, I have a doubt.

In option D, there are two that-s. The first one is referring to the visible equipment, the second one is referring to the amount of energy.

I know that someone in this thread has already asked the same question and someone is talking about all sorts of technical reasons/explanations for such usage—demonstrative pronouns etc etc.. I don’t really understand the technical jargon.

how can the same pronoun “that” have two antecedents??

Please help.

Looking forward to hearing from you guys

Best regards,

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