GPrep

Providing initial evidence that airports are a larger source of pollution than they were once believed to be, environmentalists in Chicago report that the total amount of pollutant emitted by annually by vehicles at the O'hare International airport is twice as much as that which is being emitted annually by all motor vehicles in the Chicago Metro area

A) as much as that which is being emitted annually by all
B) as much annually as is emitted by the
C) as much compared to what is annually emitted by all
D) that emitted annually by all
E) that emitted annually compared to

OA : D
Can some one explain as what's going in the question and each of the wrong answer choices ?

I narrowed it down to B and D and chose B.
My reasoning
A) awkward ..that which
C) As much as .. as much ..what is wrong

compared to is used for comparing dissimilar things. hence C & E out.

I was hung on B & D but ruled out B after more than 2 min.

I believe there is a typo in the Q that threw me off initially (extra by)

I felt that D is parallel. amount of P emitted annually by vehicles at ORD is twice that emitted annually by all V in Chicago area.

If you look at B, amount of P emitted annually by vehicles at ORD is twice as much annually as is emitted by the V in Chicago area.

uses is to denote the amount of pollution.

moves the word annually around to split as much as. I found it awkward but it might be ok just like "such as" is divided in some GMAT questions

removes the word all.

This is a rarity: a problem mostly about clarity and concision.

A: incorrect: "which is being" -- beware "is being" -- we generally want to limit the number of "to be" verbs, and here we have two, back-to-back

B: incorrect: the placement of "annually" no longer described "emitted"

C: incorrect: unidiomatic: "twice as much compared to" should be "twice as much as" or simply "twice." "Compared to what is" is also not concise (same pattern as A).

D: correct

E: incorrect: redundant -- we do not need "compared to" again

Would this form be correct ?

the amount of pollution emitted annually by.. is twice as much as that emitted annually by ...
Here 'that' refers to amount of pollution

actually, i don't think so. i think the combination of "amount" and "as much as" would be tagged as redundant and therefore wrong.

i am not 100% on this, as the gmat's usage preferences are rather slippery at times, but there's no doubt that this suggestion is inferior to the version without "as much as".

shorter versions:
amount X is twice as much as amount Y --> inferior, and possibly even wrong (redundant)
amount X is twice amount Y --> undoubtedly better

Hi JonathanSchneider,

Can't we kick out the options based on the following reasoning ?

A) as much as that which is being emitted annually by all
being....is incorrect.

B) as much annually as is emitted by the
All is missing.

C) as much compared to what is annually emitted by all
As missing.

D) that emitted annually by all
Correct.

E) that emitted annually compared to
All missing.

you can't just reflexively kick out "being" 100% of the time, although it is indeed wrong in most cases.
there have been a couple of problems in which "being" has been correct - and, in those problems, it has appeared in a passive-voice construction (being VERBed) a lot like this one.
but in this case, "being" doesn't make sense because it's not parallel to anything in the earlier part of the construction.


no, i wouldn't eliminate for this reason.
even if you just say "...by the motor vehicles in the chicago metro area", the meaning is the same as it would be if you'd included "all". the "all" serves to add emphasis, but doesn't really change the meaning.

the real problem is that "is" has no parallel in the first part of the comparison - i.e., the first part doesn't say "is emitted" or "are emitted" - and so the comparison is wrong.


correct. if you say "twice as much", you need "as..."
also note that "twice as much" can't be paired with "compared to".


nope, i wouldn't eliminate on this. see (b).
but there are BIG BIG problems with this answer choice.
note first that you have both "twice" and "compared to"; that's incorrect, as jonathan has noted above.
second, note that you have "compared to motor vehicles...", which implies that we are making a direct comparison between pollutants and motor vehicles (rather than between pollutants and pollutants, as in the correct answer. that's nonparallel and thus wrong.

Ron,

In correct answer D, can we assume that the word "that" refers to pollutant emitted annually? or just pollutant?

I am often confused by what the word "that" really refers to when "that" is used to abbreviate a sentence.

In general, I see the word "that" used to reference a noun or noun phrase. Would "that" ever be used to refer to a verb or verb phase?

this is parallelism.
just look at the parallel structures side-by-side, and notice which parts match up to which other parts.

i.e.
the total amount of pollutant emitted annually by vehicles at the O'hare International airport
is twice
that emitted annually by all...

so, "that" stands for everything that's orange.



no. it's a PRONOUN. (i.e., it's not a "pro-verb").
pronouns can only stand for nouns.

TWICE THAT DOUBLE!
This does create a confusion in my mind on the usage of "that"...

Might be being from engineering background i always associate twice with twice of..."12 is twice of 6.."
and i was not able to mark (d) as i felt that an "of" was missing in the option and that it should have been ...
twice "of that emitted annually by all...."

i guess i need to rewire my natural thinking but just want to make sure that i am getting it right...
Usage : X is twice that Y
1)The total money i have is twice that you have.
2)The total money i have is twice of what you have.
3)the total money i have is twice of that you have.
4)the total money i have is twice as much as you have.
5)the total money i have is double of what you have.

Here X was uncountable..lets take X as countable...does that change anyhting?
6)The number of books i have are twice that you have.
7)The number of books i have are twice as many as you have.
8)the number of books i have are twice of as many as you have

Please suggest me on correct and incorrect ones with some reasoning...
i know i am making it a little complicated but getting this right would mean clearing the "that, twice and double" confusion once and for all:)

thanks.
ankur.

ankur --
this may be a regional distinction -- perhaps english is structured differently in the country where you were educated -- but a single construction “twice of ...” would always be considered incorrect in american english.
the only way you're going to have "twice" next to "of" is when they're parts of completely different constructions; see #3 below.

basically, there are three different kinds of acceptable uses of “twice”:
1) twice NOUN/PRONOUN, where the noun or pronoun describes a numerical quantity of something;
2) twice as ADV/ADJ (as)... / twice this/that ADV/ADJ
3) twice by itself, meaning that something has happened two times (e.g., i've been there twice).

#3 is the only one of these constructions in which you might see "twice" followed by "of" -- and then only if they're independent constructions.
for instance, you could say
smith has already been advised twice of the foolishness of these actions.
... notice that this construction is NOT "twice of"; the "of" is part of the boldfaced construction, but the "twice" is not.

note that, in #1, there may be possessives and/or adjectives in front of the NOUN.

--

your examples:


this isn't a construction.
you're only going to have "twice that..." in one of the following 2 cases:
1) "that" is a relative pronoun (e.g., the unemployment rate of Country X is twice that of Country Y)
2) they're part of independent constructions (e.g., smith has already been advised twice that these actions are foolish)


incorrect -- this "that" is not a relative pronoun such as the one above.


both incorrect -- "twice of X" is never correct as a single construction.


"twice as much as you have" is ok.
"total money" isn't, though; you'd have to say "the amount of money" or "the total amount of money".


incorrect -- the correct construction is "double X", not "double of X".



incorrect, same reason as #1

also, note that "the number ... are ..." is incorrect in all of these sentences; "the number" is singular, so the verb should be "is".


"twice as many as ..." is a correct construction.
you can't say "the number is twice as many", though -- that's a redundant construction.
you'd just say "i have twice as many books as you have."


wrong. can't have "twice of X".

Thanks Ron!
After some SC practice , i too see twice "of" as awkward ;)

regards,
ankur.

glad to be of assistance.

Hi Ron,

Can you please explain how : "that" is a relative pronoun when used in :"the unemployment rate of Country X is twice that of Country Y " and "that" is not a relative pronoun in "The total money i have is twice that you have".

How can we distinguish among these two "that"s?

Appreciate your quick response as I have the G-Day early next week.

with warm regards,
Siddhartha.

it might be a relative pronoun (to be honest i don't really know), but that construction is wrong.

if you're going to use "that" to REPLACE a noun, then it needs to be followed by a MODIFIER, not a subject + verb.
e.g.
the population of argentina is more than ten times that of uruguay.
--> here, "that" actually REPLACES "population" (which is omitted from that second construction as a result). appropriately, it's followed by “of uruguay”, a prepositional phrase modifier.

if you use a "that" FOLLOWING the noun to which it refers, THEN you can follow with a subject + verb.
the bag that i left on the table is gone.
--> here, "that" does not replace "ball", which is sitting right next to it.

--

in any case, if the distinction is troubling you (and especially if your test is really soon), you should probably just ignore it -- i don't think i've ever seen this sort of construction on an official problem. remember, it was introduced randomly by one of the posters, not by gmac.