Over the course of the eighteenth century, the average output of ironw

Over the course of the eighteenth century, the average output of ironwork tripled as a result of several improvements in blowing machinery and because coal replaced charcoal as the fuel used in the smelting of iron ore.

A. Over the course of the eighteenth century, the average output of ironwork tripled as a result of several improvements in blowing machinery and because coal replaced charcoal as the fuel used in the smelting of iron ore.

HEY GUYS, A SIMPLE WAY TO ELIMINATE B
coal replaced charcoal as the fuel
the replacement of charcoal by coal for the fuel, "FOR" IS WRONG HERE

replace X with/by Y as sth
substitute X for Y

DON'T MIX THE IDIOMS, I THINK I DESERVE KUDOS!!
Please correct if I'm wrong.

B. Over the course of the eighteenth century a tripling in the average output of ironwork was due to the replacement of charcoal by coal for the fuel used in the smelting of iron ore, in addition to several improvements in blowing machinery.

C. With charcoal's being replaced by coal as the fuel used in the smelting of iron ore and several improvements in blowing machinery, the average output of ironwork tripled over the eighteenth century.

D. The replacement of charcoal with coal for the fuel used in the smelting of iron ore and several improvements in blowing machinery, the average output of ironwork tripled over the eighteenth century.

E. Charcoal being replaced by coal as the fuel used in the smelting of iron ore, and several improvements in blowing machinery, which tripled the average output of ironwork over the course of the eighteenth century.

GMATNinja Sir! Your explanation is desperately needed here. Why did we prefer a (A) over (B)?

This one is all about meaning.

First, take another look at (A):

The sentence begins with the modifier in red. This phrase appears to be giving us the time frame for the action "tripled." This makes perfect sense. During this century, output tripled. So the output may have gone up a bit in 1714 and gone up some more in 1716, and over the course of this 100-year period, the increase accumulated so much that output tripled. Totally logical.

Contrast this with (B):

As Karishma noted in an earlier post, this modification makes no sense. "Over the course of the century," the tripling was due to the replacement of coal? What does that mean? That in 1714, the tripling was due to the replacement of coal and in 1716, the tripling was also due to the replacement of coal, and so on? Did the output triple every year over the course of the century and each time it tripled, it had the same cause? This is illogical.

The problem is that "over the course of 100 years" suggests a gradual process, but "was due to" isn't a gradual action that unfolds over time, the way "tripled" is.

Because (A) is logical and (B) is not, (A) is better.

I hope that clears things up!

GMATNinja Thankyou for the explanation. But in (A) we compare a noun improvements with a clause coal replaced charcoal. How are they parallel. I understand that the logic and meaning trump everything else, but how to look beyond parallelism within 1.8 minutes during GMAT?

The parallelism does get a bit tricky here.

What we're actually listing are reasons why the average output of ironwork tripled over the course of the eighteenth century: the average output of ironwork tripled (1) as a result of several improvements in blowing machinery and (2) because coal replaced charcoal as the fuel used in the smelting of iron ore.

Notice that "as a result" is basically a synonym for "because" here, so it seems perfectly reasonable for "as a result" and "because" to be parallel. To your point, the things that come after "as a result" and "because" are certainly not parallel. But notice how hard it would be to actually make the two reasons parallel:

• The second reason has a very specific subject and object (coal replaced charcoal). But the first reason is completely different. It's a series of improvements in blowing machinery made by unknown (and presumably numerous) subjects.
• So how could we write the first reason to be parallel to the second? Maybe "because inventors/machinists/people made several improvements to blowing machinery"? But, again, what if we have no idea who actually made those improvements? At best, we have to introduce a vague and unnecessary subject that makes the sentence even more complicated.
• You could also make the second part more grammatically parallel to the first (maybe "charcoal's replacement by coal" or "coal's replacement of charcoal"), but notice that those options are awkward and less clear than the straightforward phrase "coal replaced charcoal".

Could we make the elements in the list a bit more parallel? Sure, but doing so would make the sentence LESS clear. Since we basically have "(1) because ____ and (2) because ___" -- and since the elements in the list are logically parallel (both are reasons why the average output of ironwork tripled) -- you can hang on to (A) and look for other decision points.

I hope that helps a bit!

A. Over the course of the eighteenth century, the average output of ironwork tripled as a result of several improvements in blowing machinery and because coal replaced charcoal as the fuel used in the smelting of iron ore.
Since independent clauses are use we need a comma and the meaning is perfect therefore let us hang on to it

B. Over the course of the eighteenth century a tripling in the average output of ironwork was due to the replacement of charcoal by coal for the fuel used in the smelting of iron ore, in addition to several improvements in blowing machinery.
a comma is necessary after 18 th century and the meaning isn't correct

C. With charcoal's being replaced by coal as the fuel used in the smelting of iron ore and several improvements in blowing machinery, the average output of ironwork tripled over the eighteenth century.
being isn't preferred since it's never the right answer and the intended meaning is also not correct

D. The replacement of charcoal with coal for the fuel used in the smelting of iron ore and several improvements in blowing machinery, the average output of ironwork tripled over the eighteenth century.
The addition of comma isn't correct since these are not independent clauses and the meaning isn't akward

E. Charcoal being replaced by coal as the fuel used in the smelting of iron ore, and several improvements in blowing machinery, which tripled the average output of ironwork over the course of the eighteenth century.
Similar reasoning as C and which in the end isn't appropriate

Therefore IMO A

" a trippling " is wrong. "tripling" is a gerund, which can not go with article "a" or "the" and can not go with adjective. this is syntactic feature of gerund. this is purely grammatical.
"bad failing" is wrong.
"a failing' is wrong.

there is no pure noun "tripling" and "failing". normally, if there is no doing as pure noun, there is some pure noun such as "failure" or " triple".

some form of doing work as pure noun, which can go with article and adjective. "good learning" , "a learning" are correct because "learning" is pure noun.

verb can be categorize into 3 kind
- a state, which exist indefinitely. she is beautiful
- a process which terminate. I close the door
- a process which is durative. I am eating the lunch.

doing, such as tripling , is used to show a process. but inhere , we focus on a process which terminate, the action of trippling, which terminate, so, the verb "trippled" is good and logical.

if we say, as in choice B, "trippling is due to" , we want to say that the output have not trippled but in the process of trippling.

we dont have to know about trippling to solve this problem. but when we face a choice between doing and noun or verb, doing is normally wrong.

egmat verbal team,
could you help me understand the error in my analysis of option choice A

Meaning analysis: The average output of iron tripled during the 18th century because of two things:
1. Several improvements in blowing machinery
2. Coal replacing charcoal as fuel used in smelting of iron ore

Error analysis: As per my conceptual understanding, I understand that parallel entities should be logically and grammatically parallel. While the entities "several improvements" and "coal replacing..." are logically parallel, I rejected option A because I felt that "several improvements" is not parallel to "because charcoal replaced...."
And additionally, I also felt that the idiom "as a result of X and because Y" is also incorrect

Request if you could please help me understand where I am going wrong with my analysis.

Thanks in advance.

Hello Casp,

Thank you for the query.

Your meaning analysis is perfect. The sentence indeed presents two reasons for an effect. You are also correct ins saying that the two reasons do not appear to be parallel. So, here the meaning is fine, but the grammar appears to be off.

However, if you analyze the other four answer choices, you will find that they compromise on both aspects - grammar and logic. Therefore, Choice A emerges as the best among the rest.

This certainly is an atypical question. However, arriving at the correct answer choice is not difficult in this question.


Hope this helps.
Thanks.
Shraddha

Hi KarishmaB - when it comes to option B - you mention "Was" indicates a point in time.

But dont we say --

Over 18th century, Britain was the strongest superpower nation

Here the sentence uses the word "Was" - However, even with the usage of "Was" -- Britain has this quality OVER 1700 - 1799 and not in a specific timeframe (sas 1750 only) and is not a superpower in another time frame (say 1760)

I thhink the above sentence is clearly referring to Britain having this quality OVER 100 years.

Its clear that Britain was a super-power from 1700 - 1799.

Same thinking in option B

I thought - the tripling was taking place due to X and due to Y --- this reason (Due to X and Due to Y) was TRUE OVER 100 years (1700 - 1799) and not only in 1750 for example.

"was" is used to describe a state when we say "Britain was the strongest..." which lasted for many years and that is fine.

But what is our intent in our original sentence? To say that the average output tripled over this time period due to many improvements.
So we say "output tripled..." or "output was increasing..." during a period in the past.

But (B) says "tripling was due to many improvements..."

Dear Friends,

Here is a detailed explanation to this question-
Concepts tested here: Comparisons + Parallelism + Idioms + Awkwardness/Redundancy

• “like” is used for comparing nouns, “as” is used for comparing actions/clauses, and “such as” is used for giving examples.
• All elements in a list must be parallel.
• “as A as B” is a correct, idiomatic usage.

A: This answer choice incorrectly uses “like” to provide the examples of “tar sands”, “heavy oil”, and “shale”; remember, “like” is used for comparing nouns, “as” is used for comparing actions/clauses, and “such as” is used for giving examples. Further, Option A fails to maintain parallelism among “tar sands”, “heavy oil”, and “in shale”; remember, all elements in a list must be parallel. Additionally, Option A incorrectly uses the unidiomatic construction “as A than B”; remember, “as A as B” is a correct, idiomatic usage.

B: This answer choice incorrectly uses “like” to provide the examples of “tar sands”, “heavy oil”, and “shale”; remember, “like” is used for comparing nouns, “as” is used for comparing actions/clauses, and “such as” is used for giving examples. Further, Option B fails to maintain parallelism among “tar sands”, “heavy oil”, and “in shale”; remember, all elements in a list must be parallel. Additionally, Option B incorrectly uses the unidiomatic construction “as A than B”; remember, “as A as B” is a correct, idiomatic usage. Besides, Option B uses the needlessly wordy phrase “than are”, leading to awkwardness and redundancy.

C: This answer choice fails to maintain parallelism among “tar sands”, “heavy oil”, and “in shale”; remember, all elements in a list must be parallel. Further, Option C uses the needlessly wordy phrase “as are”, leading to awkwardness and redundancy.

D: Correct. This answer choice correctly uses “such…as” to provide the examples - “tar sands”, “heavy oil”, and “shale”. Further, Option D maintains parallelism among “tar sands”, “heavy oil”, and “shale”. Additionally, Option D correctly uses the idiomatic construction “as A as B”. Besides, Option D is free of any awkwardness or redundancy.

E: This answer choice incorrectly uses the unidiomatic construction “as A than B”; remember, “as A as B” is a correct, idiomatic usage.

Hence, D is the best answer choice.

To understand the concept of "Like" vs "As" on GMAT, you may want to watch the following video (~2 minutes):



All the best!
Experts' Global Team

just to understand parallelism in A]

as a result of several improvements in blowing machinery AND because coal replaced charcoal as the fuel used in the smelting of iron ore.


we have an adverbial phrase(as a result of) made parallel to a clause (coal replaced charcoal)

Please guide.

Hello himanshu0123,

Hope you are doing good.

I agree that parallelism in this sentence does appear weird. The list looks nothing like what the SC courses teach us, right? The first entity is a phrase, while the second is a clause. How on earth can they be parallel?

If these are some questions that are bothering you, then read on.

To understand what's going on in this sentence, we must first understand the underlying principle of parallelism. What makes a list in a sentence? Those entities that perform the same function in a sentence make a list of parallel entities. Most of the time, these parallel entities are structurally and grammatically identical. But sometimes, we do come across sentences, of course, once in a blue moon, in which the elements are not structurally parallel, but they still qualify as legit parallel entities because they perform the same function in the sentence, complying with the underlying principle for the correct usage of parallelism.

This compliance with the underlying principle qualifies the list in this official sentence as correct. The two entities in the list present reasons for the same effect. Also, other answer choices have blatant errors. So, Choice A is our best bet in this official question.

Hope this helps.
Please let me know if you have any follow-up queries on this question or anything SC.
Happy Learning!!
Shraddha.

Hi avigutman - do you see the meaning of (B) as illogical (As is mentioned by experts (here and here)
?

I dont see (B) as illogical.

I agree that (B) shifts the focus of the intended meaning, but i dont think this new intended meaning of (B) as fundamentally illogical


(A) is saying -- the output tripled over 1700 - 1799.

(B) is saying :

Over 1700 - 1799 : the tripling WAS due to X and Y.

I dont understand what is illogical about this

^^ avigutman -

If i try using some analogies



Now, lets use an analogy with Due to



Simirlarly, I dont see what is fundamentally illogical about (B) -- the 2 reasons (X and) are describing something about "Tripling" -- this description about the subject was true over 1700 - 1799