Diesel engines burn as much as 30% less fuel than gasoline engines of

Yes, you would need "and emit" for parallelism and you cannot use "fewer" with carbon dioxide. It emits less carbon dioxide and fewer other gases (say only 2 of the 10 other gases that cause global warming).

lets talk about the pattern
main clause +comm doing
in this pattern, comma doing can stand before or after the main clause
leaning gmat well, I get into Havard.
I learn gmat, making my english better.

the point here is that only some but not all conjunction can stand before doing to add some meaning
instead of leaning english, I go out for change
as well as leaning english, I leanr French.
in the above pattern, doing refers to the subject and modifies the whole clause. there are many , but not all, meaning relation between doing and the main clause.

because of learning hard, I pass gmat.

this is wrong because "because of" can not stand doing when doing refer to the subject -when doing is participle-.

" as well as" normally connect 2 similar things. I learn english as well as french.
but those phrases can stand before doing. doing in this case is participle, which has some, but not all, fuctions of adjective and verb. I dont know whether these phrase are conjunction or preposition when they stand before doing. but the key point is they can stand before doing this way

doing could be a pure noun , a participle or a gerund. pure noun can go with article such as "a, the" and adjective. participle has some, but not all , functions of adjective and has some but not all, functions of verb. gerund has some, but not all , function of noun and has some but not all, functions of verb.

doing is basic grammar point and gmat test this point a lot. but the problem is that most grammar books do not explain doing well and, non native test take fail on many SC problems.

many basic and hard points gmat tests because they are basic. but these points is not explained well in grammar books. for example, present perfect is not well explained in most grammar books though this point is basic. we come to this forum just to see the explanation from successful test takers who , though successful, are native to english and, so, can not give full explanation of those basic point of grammar. worst, the non natives read grammar books and focus on hard and not-basic points of grammar.

Can someone please elaborate on why emit is not a better choice than emitting?

Hi TalonShade,

There are a couple of things we should keep in mind here:

1. It is possible to use the -ing form of a verb after as well as.

2. We should probably not take a call on the emit vs. emitting split. Some people may find emit better, but others will insist that we use the -ing form after as well as.

The point is that there's nothing in this question that tells us that the GMAT considers either emit or emitting to be incorrect. This is most likely something that they added so as to distract test takers.

I'll echo Ajitesh: the biggest source of confusion here is that test-takers often treat "as well as" the same way they'd treat "and." But they're not the same. "And" is a parallelism marker. "As well as" doesn't have to be.

For more on that distinction, check out this post.

Diesel engines burn as much as 30% less fuel than gasoline engines of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have been implicated in global warming.


(A) of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have

(B) of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having

(C) of comparable size, and also they emit far fewer carbon dioxide and other gasses that have

(D) that have a comparable size, and also they emit far fewer of the other gasses having

(E) that have a comparable size, as well as emitting far fewer of the other gasses having





1. less/fewer
2. s+v+o, as well as ving
s+v+tov2+o, as well as v2
s+v+o as well as s+v: comparison
3. one/the other
4. N+that have vpp/N+having

Choice A (the OA) is poor construction, because of the phrase "as well as requiring" and its complete lack of parallel structure. However, GMAC says it's the answer, so we have no choice but to learn from that.

"The GMAT is a challenging test, as well as requiring the student to pay a $250 exam fee." is not an English sentence that one should ever speak or write in real life...but it's permissible, according to GMAC.

The only real takeaways from this highly flawed SC question? If GMAC says it's correct, then it's correct—and correct answers do not have to be perfect, or even close to perfect. Yes, Choice A is bad, but choices B, C, D, and E are all worse.

The sentence would obviously read much better as "The GMAT is a challenging test that requires the student to pay a $250 exam fee." or "The GMAT is a challenging test, one that requires the student to pay a $250 exam fee."

Hi experts,

I got this question wrong and after going through the forums I could not find my doubt/error.

I eliminated Option (A) since "less" was not in the comparative form.

Why do we use "fewer" in Option (A) but not "lesser"?

Thanks!

The opening clause tells us that diesel engines burn less fuel than gasoline engines, so when we see "less carbon dioxide," we can assume that we're getting a similar comparison. There's no need to restate "than gasoline engines" since that's already been established. And because carbon dioxide is not itself countable, "less" is appropriate. ("Lesser" has a different meaning altogether, suggesting something to the effect of "not as great." We use "less" when comparing uncountable quantities.)

"Fewer" is describing "other gases." Because gases are countable, "fewer" is correct here.

I hope that clears things up!

Hey test9032

Happy to help you with this.


Your confusion is understandable. A lot of students get confused between the words 'less' and 'lesser'. Allow me to set the record straight.

"Less" is the uncountable counterpart of the word 'fewer'. 'Fewer' is used with countable nouns; whereas 'less' is used with countable nouns. Here are a few examples:
a. The people care less about the environment than about their comfort.
b. I earn less than I spend.
c. The more friends we have, the less lonely we feel.


"Lesser" is an adjective that means "not as great in size, amount or importance as something/somebody else". Let's look at some examples:
a. A lesser man would have given up.
b. The Gods ignore us lesser mortals.
c. He pleaded guilty to the lesser offence.


So, as you can see, the word of comparison is 'less' and not 'lesser'.

I hope this improves your understanding.

Happy Learning!


Abhishek
SME & Product Creator
e-GMAT

Here is my complete explanation of this question that bothers many people.

The sentence tells us that Diesel engines burn less fuel than gasoline engines. They also emit less carbon dioxide and far fewer of the other dangerous gases.

The first decision point is ‘as well as’ vs ‘and also.’ Usage of neither is incorrect.
‘and’ is a conjunction and will take a verb after it while ‘as well as’ is a preposition and will take a noun/gerund after it. Hence, both ‘as well as emitting’ and ‘and also emit’ make sense. Yes, ‘also’ is redundant here but sometimes we use it for emphasis so I cannot eliminate options based on that. I will prefer ‘as well as emitting’ but not rule out ‘and also emit’.

(B) of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having

Option (B) uses ‘as well as emit’ which is incorrect. We need a noun/gerund after ‘as well as.’
Also, we do not need parallel structure with ‘as well as’ because it does not join equal elements. When ‘and’ joins elements, then they are parallel.

(C) of comparable size, and also they emit far fewer carbon dioxide and other gasses that have
(D) that have a comparable size, and also they emit far fewer of the other gasses having
(E) that have a comparable size, as well as emitting far fewer of the other gasses having

In options (C) and (D), ‘and also they emit…’ have multiple redundancies. Here ‘they’ is also redundant because the subject here is the same as the subject of the previous clause ‘diesel engines.’ So we do not need to repeat it.

Diesel engines burn less gasoline and emit far lesser 〖CO〗_2… (correct)

Also, it is better to use ‘that have been implicated’ and not ‘having been implicated.’
‘Having been implicated’ would normally require another action. It begs the question – then what?
Having been implicated in the case, he decided to meet a lawyer.

When we use only ‘having been implicated’ it seems to suggest that they were implicated and are not implicated any more. Hence options (A) and (C) are better than (B), (D) and (E).

Option (C) commits the blunder of using far fewer (countable) with the quantity of carbon dioxide gas (uncountable).

Options (D) and (E) fail to mention carbon dioxide while mentioning ‘other gasses’ later on. When we say ‘other gasses,’ we need to have mentioned some gasses specifically before.
Hence, options (B), (C), (D) and (E) have multiple errors.

(A) of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have

Option (A) is correct and preferable on all counts.

Answer (A)

Hi GMATNinja,

Would you please help to explain more detail about why 'having been' is wrong in B?
Isn't 'having been' a short form of 'that have been'?

Thank you so much.

You might want to check out this post first for more on "having been": https://gmatclub.com/forum/with-near-to ... l#p3217601.

"Having been" is generally used to explain how one action affected another. Here's an example, borrowed from the linked post above:

"Having been pummeled by a series of large waves while trying to paddle out on his surfboard, Tim lacked the energy necessary to actually catch and ride a wave."

In this case, the "pummeled" part explains why Tim lacked the energy.

Or, riffing on choice (B):

"Having been implicated in global warming, the refrigerant R-22 was banned by the government."

Here, the "implicated" part explains why the refrigerant was banned.

In choice (B), "other gases" doesn't have a verb, so there's no action for the "having been" part to modify. As a result, a reader might even think that the "having been" part modifies "diesel engines" and its verbs ("burn" and "emit").

In other words, we expect "having been" to modify a clause (noun+verb), not just a noun. Since "other gases" is just a noun (an object of the preposition, if you want to get technical), it makes sense to modify it with a noun modifier (e.g. "that have been..."). That makes (A) a better choice than (B).

I hope that helps!

Diesel engines burn as much as 30% less fuel than gasoline engines of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have been implicated in global warming.

Option Elimination - Don't boil your blood on this, as GMAT can throw exceptions at us, and there is a high possibility that we don't know. The key message that this question drives home is that while "and" works as a conjunction (with equal stress on both sides of "and" elements), "as well as" can function as a conjunction (though a bit different than "and" in terms of its use to present an additional element that's related or supportive of the main element. For example, Ram, as well as Shyam, is doing well. Here, the verb is "is" as "as well as" unlike, "and" doesn't make the subject plural. Or Let's further complicate a bit. Ram, as well as his brothers, are doing well. So here, we use "are" not because we have people joined by "as well as" but because the subject closer to "as well as" is plural.) At the same time, "as well as" can also function as a preposition, opening doors for "as well as" to do a lot more. As with any prepositional phrase, it can modify nouns or verbs. Had there been a simple prepositional or subordinate conjunction after the comma, we would have treated it generally as we know it can act adverbial, but the usage of "as well as" that we assumed the majority of times as "and" though differently as we now know, trips us off.

Option Elimination -

(A) of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have - using "as well as" as a preposition, but once we know that "as well as" can function as a preposition, it's much easier. Comma + prepositional phrase is acting adverbially on the preceding clause: "Diesel engines burn." ok.

(B) of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having - now as we know that "as well as" after the comma is acting as a prepositional phrase, so it is wrong to use "verb" after a preposition. Prepositions can have nouns, noun phrases, pronouns, or gerunds, but verbs. Another bigger issue is "having been implicated." Don't get allergic to "having been," which can be right if used properly. "Having been" is used with a past event before another past event: E.g., Having finished the work, John went for a walk. On a different note (isn't then the role of "having been" the same as past perfect? No. Because "having been" is different from past perfect. In the past perfect, the action has been completed before another past action, but in the present perfect participle, the effect of that action (that occurred before another past action) is still present. Now, back to our question, there is no other past action after "having been, so this usage is incorrect.

(C) of comparable size, and also they emit far fewer carbon dioxide and other gasses that have - "few" countable with Carbon Dioxide. No. "and also" is a red herring. Yes, it's redundant, but it can be used to put more stress on something. E.g.; I enjoy playing tennis, and I also love swimming. The conjunction "and" connects the two activities (playing tennis and loving swimming), while "also" emphasizes that swimming is another activity the speaker enjoys.

(D) that have a comparable size, and also they emit far fewer of the other gasses having - "having" issue.

(E) that have a comparable size, as well as emitting far fewer of the other gasses having - "having" issue.