Because natural gas is composed mostly

[Steve]

Because natural gas is composed mostly of methane, a simple hydrocarbon, vehicles powered by natural gas emit less of certain pollutants than the burning of gasoline or diesel fuel.
(A) less of certain pollutants than the burning of gasoline or diesel fuel
(B) fewer of certain pollutants than burning gasoline or diesel fuel do
(C) less of certain pollutants than gasoline or diesel fuel
(D) fewer of certain pollutants than does burning gasoline or diesel fuel
(E) less of certain pollutants than those burning gasoline or diesel fuel

I know you use the word less when the noun is "uncountable" and the word fewer when the word is countable, i.e. you can put a number in front of it.

I feel like you can put a number in front of "certain pollutants", which is why I chose 'D'. For example, you can have 3 certain pollutants.

OA is E. Please explain. Thanks!

[Guest]

Because natural gas is composed mostly of methane, a simple hydrocarbon, vehicles powered by natural gas emit less of certain pollutants than the burning of gasoline or diesel fuel.
(A) less of certain pollutants than the burning of gasoline or diesel fuel
(B) fewer of certain pollutants than burning gasoline or diesel fuel do
(C) less of certain pollutants than gasoline or diesel fuel
(D) fewer of certain pollutants than does burning gasoline or diesel fuel
(E) less of certain pollutants than those burning gasoline or diesel fuel

B, D is incorrect. Pollution is not countable, thus less must be used.

A, C is incorrect. Those must be used to refere back to vehicles that's powered by gasoline or diesel.

[Steve]

I'm still getting stuck.

While I agree that pollution is uncountable, I still feel like pollutants are countable. For example, I know they count CO2 (a pollutant) - could be 385 parts per million.

[RonPurewal]

I'm still getting stuck.

While I agree that pollution is uncountable, I still feel like pollutants are countable. For example, I know they count CO2 (a pollutant) - could be 385 parts per million.

* first of all, the point is moot, as (e) is the only answer choice whose parallelism is anywhere close to correct. the first part of the parallel structure refers to vehicles; (e) is the only choice in which the second part likewise refers to vehicles.

* fewer of those pollutants and less of those pollutants have different meanings.
the former means that, if you made lists of the pollutants from each of the two sources, then one of the lists would be missing pollutants that were on the other list.
the latter means that both lists would contain the same pollutants, but that the quantities would be lower on one side.

* finally, if a substance or quantity is measured with numbers and units - such as 385 ppm - you generally use "uncountable" constructions. for example, all of the following are correct (and the corresponding constructions with "fewer" are incorrect):
this cd cost less than $15.
i weigh less than 215 pounds / my body weight is less than 215 pounds.
the concentration of co2 in the atmosphere is less than 400ppm.
if you care about the underlying linguistic reason, it's because we aren't literally counting these units; they're merely a convenient representation of the underlying uncountable quantity, such as money, weight, or co2 concentration. if you need even more of a rationale, note that i could weigh 214.24235 pounds, and that the co2 concentration could be 375.239857 ppm; if these were countable things, both of those statements would be absurd.

[H]

How come E doesn't have a "do" at the end?
Without the "do", isn't the sentence ambiguous?
Without the "do", "those" can have two potential referents: "vehicles" and "pollutants".
Am I missing something?

[RonPurewal]

Without the "do", isn't the sentence ambiguous?

if this is indeed an official problem, then you have just learned that the official answer to this question is "no, the sentence is not ambiguous".
take note.
remember, when you see an official answer with which you disagree (and there will be some of those), the idea is that you should learn from that answer, not fight against it.

--

incidentally, if the word "do" were to be placed into this sentence, it would NOT go at the end; that's not where those sorts of auxiliary verbs are placed in formal written english. rather, they come before the subject: than do those burning gasoline or diesel fuel.
compare this version with the version you'd get by placing "do" at the end, and you'll see the reason for the rule; the former is way easier to read and parse.

[tankobe]

* fewer of those pollutants and less of those pollutants have different meanings.
the former means that, if you made lists of the pollutants from each of the two sources, then one of the lists would be missing pollutants that were on the other list.
the latter means that both lists would contain the same pollutants, but that the quantities would be lower on one side.

* finally, if a substance or quantity is measured with numbers and units - such as 385 ppm.

i agree, Ron!
But what if i change less of into less---less certain pollutants, still OK?
i know certain is crucial--as a restrictive Adj--here, waht if less pollutants/less gases/less salts?

[RonPurewal]

i agree, Ron!
But what if i change less of into less---less certain pollutants, still OK?
i know certain is crucial--as a restrictive Adj--here, waht if less pollutants/less gases/less salts?

nope, that won't work.

there is, however, a rather obscure use of "less", in which it basically means the same thing as "minus".
for instance: "net weight" refers to the total weight of the parcel, less the weight of the container.
i'm not sure whether this construction has ever appeared, or will ever appear, in an official problem, but it is definitely an acceptable use of "less".

[7ewis.chen]

Without the "do", isn't the sentence ambiguous?

if this is indeed an official problem, then you have just learned that the official answer to this question is "no, the sentence is not ambiguous".
take note.
remember, when you see an official answer with which you disagree (and there will be some of those), the idea is that you should learn from that answer, not fight against it.

--

incidentally, if the word "do" were to be placed into this sentence, it would NOT go at the end; that's not where those sorts of auxiliary verbs are placed in formal written english. rather, they come before the subject: than do those burning gasoline or diesel fuel.
compare this version with the version you'd get by placing "do" at the end, and you'll see the reason for the rule; the former is way easier to read and parse.

So, Ron u do acquiesce that choice E with do --- less of certain pollutants than do those burning gasoline or diesel fuel --- is correct?

Cuz I saw this question.

An exceptionally literate people, more Icelanders publish books per capita than do the people of any other nation.
A. more Icelanders publish books per capita than do the people of
B. more Icelandic books are published by Icelanders per capita than by the people of
C. Icelanders publish more books per capita than do the people of
D. Iceland’s per capita publication of books is higher than that by
E. the per capita publication of Icelandic books is higher than that in

The answer of the question above is C which is with auxiliary. Why we need auxiliary here but on the first question (or we could add auxiliary on the first question?)

[RonPurewal]

Without the "do", isn't the sentence ambiguous?

if this is indeed an official problem, then you have just learned that the official answer to this question is "no, the sentence is not ambiguous".
take note.
remember, when you see an official answer with which you disagree (and there will be some of those), the idea is that you should learn from that answer, not fight against it.

--

incidentally, if the word "do" were to be placed into this sentence, it would NOT go at the end; that's not where those sorts of auxiliary verbs are placed in formal written english. rather, they come before the subject: than do those burning gasoline or diesel fuel.
compare this version with the version you'd get by placing "do" at the end, and you'll see the reason for the rule; the former is way easier to read and parse.

So, Ron u do acquiesce that choice E with do --- less of certain pollutants than do those burning gasoline or diesel fuel --- is correct?

Cuz I saw this question.

An exceptionally literate people, more Icelanders publish books per capita than do the people of any other nation.
A. more Icelanders publish books per capita than do the people of
B. more Icelandic books are published by Icelanders per capita than by the people of
C. Icelanders publish more books per capita than do the people of
D. Iceland’s per capita publication of books is higher than that by
E. the per capita publication of Icelandic books is higher than that in

The answer of the question above is C which is with auxiliary. Why we need auxiliary here but on the first question (or we could add auxiliary on the first question?)

the helping verb ("auxiliary") is only necessary when the sentence is ambiguous.
for instance:
i know more about shakespeare than my brother
--> ambiguous
this could mean:
1) i know more about shakespeare than my brother does
2) i know more about shakespeare than about my brother
... so in this case you must use one of those auxiliary verbs, because, without one, you can't tell what the sentence means.

on the other hand --
if one of these sentences is NOT ambiguous, then you have a choice -- you don't have to use the helping verb, but, should the urge strike you, you certainly can.
for instance:
i can lift more weight than my brother --> not ambiguous; this only has one possible meaning.
but ... if you want to, you can also write
i can lift more weight than my brother can.
you don't need that helping verb, but the sentence is correct either way.

in your "iceland" example, the sentence isn't ambiguous, and so would work either with or without the helping verb. (notice that there's no alternative choice without it -- that situation would involve two correct answers!)

[duyng9989]

I have two questions:

Is this question really from official GMAT SC? I found it on Q164 SC1000, which is from internet and unknown source.

Second, I still doubt the reasoning of fewer and less with polutants.

Take a look at this sentence (THis is from official Gmat prep)

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.

B. of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having
E. that have a comparable size, as well as emitting far fewer of the other gasses having

Correct answer here is E - Fewer of other gassES.

Other sentence (i only quote the correct answer)

A report by the American Academy for the Advancement of Science has concluded that many of the current uncontrolled dioxinS to which North Americans are exposed come from the incineration of waste.
[discuss here: sc-a-report-by-the-american-academy-for-the-advancement-t7508.html]

The recent surge in the number of airplane fights has clogged the nation's air-traffic control system, leading to 55 percent more delayS at airports and prompting fears among some officials that safety is being compromised

As far as I understand, if we add s after the uncountable noun, we can quantify it.

If we have "S" after uncountable now, we need to use Fewer.
Eg:
The investigations of many psychologist and anthropologists support the generalization that there is little of significant differences in underlying mental processes manifested by people from different culture. => wrong.

Correct: that theire is little that is significantly different.
[discussed here: the-investigations-of-many-psychologist-t1646.html]

Ron, what is your thought?

Thank you

[RonPurewal]

duyng9989, sorry, but i don't really understand the points you are trying to make here.

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.

B. of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having
E. that have a comparable size, as well as emitting far fewer of the other gasses having

Correct answer here is E - Fewer of other gassES.

check your source.
this is, indeed, a GPrep problem. however, the correct answer is neither of the choices you have listed here.

it's clear that you did not get this problem from the source, because "gases" is not spelled the american way. ("gasses" is a british/commonwealth spelling, like "colour" or "centre".)

--

the rest of what you wrote, i'm sorry, but i don't really understand.

in particular, you wrote something about "using 'fewer' with uncountable nouns". that's not possible; you use "fewer" with countable nouns, and "less" with uncountable nouns.

[duyng9989]

duyng9989, sorry, but i don't really understand the points you are trying to make here.

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.

B. of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having
E. that have a comparable size, as well as emitting far fewer of the other gasses having

Correct answer here is E - Fewer of other gassES.

check your source.
this is, indeed, a GPrep problem. however, the correct answer is neither of the choices you have listed here.

it's clear that you did not get this problem from the source, because "gases" is not spelled the american way. ("gasses" is a british/commonwealth spelling, like "colour" or "centre".)

--

the rest of what you wrote, i'm sorry, but i don't really understand.

in particular, you wrote something about "using 'fewer' with uncountable nouns". that's not possible; you use "fewer" with countable nouns, and "less" with uncountable nouns.

What I meant is that if uncountable nouns with "S" or "es" at the end, we use the fewer or many. Else use little or much.

I see a lot of examples in OG and Gmatprep that uncountable noun is "quantified" by adding "s" or "es" at the end.
See my examples in previous posts.


So in this sentence in the thread, I am skeptical about the source of the question.

[RonPurewal]

What I meant is that if uncountable nouns with "S" or "es" at the end, we use the fewer or many. Else use little or much.

ah, ok, i see what you're saying -- but it isn't quite right.

"fewer" always refers to things that are countable. therefore, if you see the same word used with "fewer" and (in other contexts) with "less", then that word must have two different meanings -- one of them uncountable (referring to a continuous quantity of something), and the other countable (one, two, three, etc.)
as just one example, food can be an uncountable quantity (I eat less food than I did ten years ago.)
but, food(s) can also be a countable quantity, if it refers to different dishes or types of food (I eat fewer foods than I did ten years ago, because I have a better sense of what I like and what I dislike --> this doesn't mean that i eat a smaller amount of food; it means that i eat fewer different types of food.)

if you have to choose between these forms, then there should be adequate context for that decision.
e.g.

* On this diet, you can eat all of the foods you love; you just have to eat less of those foods. --> correct
(you can still eat the whole range of foods; you just need to eat a smaller quantity of each.)

* On this diet, you can eat all of the foods you love; you just have to eat fewer of those foods. --> incorrect
(this sentence is self-contradictory; it is simultaneously saying that you can eat all of the foods and that you can't eat all of them.)

the good news here is that you don't need any sort of sophisticated knowledge to understand this. if there's enough context, then you can make the decision. if there isn't, then look for other decisions that you can make.

[duyng9989]

What I meant is that if uncountable nouns with "S" or "es" at the end, we use the fewer or many. Else use little or much.

ah, ok, i see what you're saying -- but it isn't quite right.

"fewer" always refers to things that are countable. therefore, if you see the same word used with "fewer" and (in other contexts) with "less", then that word must have two different meanings -- one of them uncountable (referring to a continuous quantity of something), and the other countable (one, two, three, etc.)
as just one example, food can be an uncountable quantity (I eat less food than I did ten years ago.)
but, food(s) can also be a countable quantity, if it refers to different dishes or types of food (I eat fewer foods than I did ten years ago, because I have a better sense of what I like and what I dislike --> this doesn't mean that i eat a smaller amount of food; it means that i eat fewer different types of food.)

if you have to choose between these forms, then there should be adequate context for that decision.
e.g.

* On this diet, you can eat all of the foods you love; you just have to eat less of those foods. --> correct
(you can still eat the whole range of foods; you just need to eat a smaller quantity of each.)

* On this diet, you can eat all of the foods you love; you just have to eat fewer of those foods. --> incorrect
(this sentence is self-contradictory; it is simultaneously saying that you can eat all of the foods and that you can't eat all of them.)

the good news here is that you don't need any sort of sophisticated knowledge to understand this. if there's enough context, then you can make the decision. if there isn't, then look for other decisions that you can make.

Thank you for your reply.

If so, why choice B is incorrect? Fewer pollutant(S) still make sense, right? For example, car emits CO2, SO2, and all kind of other toxic gasses. And the comparison makes sense here, vehicle powered by natural gas vs burning gasoline or diesel fuel do ( I notice that choice B omits "those", which stands for engines but burning the fuel in general still make sense).

duyng9989 wrote:
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.

B. of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having
E. that have a comparable size, as well as emitting far fewer of the other gasses having

Correct answer here is E - Fewer of other gassES.


check your source.
this is, indeed, a GPrep problem. however, the correct answer is neither of the choices you have listed here.

it's clear that you did not get this problem from the source, because "gases" is not spelled the american way. ("gasses" is a british/commonwealth spelling, like "colour" or "centre".)

Sorry, I was too hurry. The correct answer here is A. The problem is discussed here: diesel-engines-burn-as-much-as-30-less-fuel-t2129.html