The most vexing problem faced by researchers...

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The most vexing problem faced by researchers exploring wind-powered generation of electricity is achieving a constant flow of power from an unpredictable natural source that meets demand, but so the flow does not overload electrical grids with sudden voltage increases

A. achieving a constant flow of power from an unpred-ictable natural source that meets demand, but so the flow does not overload
B. achieving a constant flow of power from an unpredictable natural source, which meets demand but without overloading
C. how to achieve a constant flow of power from an unpredictable natural source, a flow that meets demand but does not overload
D. how to achieve a constant flow of power from an unpredictable natural source, but a flow that meets demand without overloading
E. how a constant flow of power from an unpredictable natural source can be achieved, which meets demand but does not overload

The correct answer C seems odd to me because of the 'Independent Clause COMMA Dependent Clause' structure:

The most vexing problem faced by researchers exploring wind-powered generation of electricity is how to achieve a constant flow of power from an unpredictable natural source is an independent clause

Then there's a comma, followed by a dependent clause

Could someone please shed light onto the usage of this structure?

It's seems odd because I'm more familiar with the Independent Clause, "FANBOYS" Independent Clause structure.

Thanks so much

Source: GMATPREP Exam Question

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by Marty Murray » Tue Dec 20, 2016 12:35 pm
Poisson wrote:The correct answer C seems odd to me because of the 'Independent Clause COMMA Dependent Clause' structure:

The most vexing problem faced by researchers exploring wind-powered generation of electricity is how to achieve a constant flow of power from an unpredictable natural source is an independent clause

Then there's a comma, followed by a dependent clause

Could someone please shed light onto the usage of this structure?

It's seems odd because I'm more familiar with the Independent Clause, "FANBOYS" Independent Clause structure.

Thanks so much

Source: GMATPREP Exam Question
Hi Poisson.

What follows the comma, "a flow that meets demand but does not overload ...", is not a dependent clause but rather an appositive.

An appositive is a word or group of words, most often a noun, noun phrase or noun clause, that modifies another word by renaming it.

Here are two simpler examples.

He put the apples and the pears into the same container, a small barrel.

"small barrel" renames and modifies "container".

The boat was caught in the flow of the river water, a strong, swirling current.

"a strong, swirling current" renames and modifies "the flow of the river water".

In the sentence created using the OA of the question, "a flow that meets demand but does not overload ..." renames and modifies "constant flow of power".

The appositive may seem like a clause, because it includes a noun, "flow" and verbs "meets" and "does not overload" but those verbs are part of a relative clause.

"that meets demand but does not overload ..." is a relative clause modifying "flow".

It's a "flow that meets demand ...", and that entire thing is an appositive renaming and modifying the "flow" that appears earlier in the sentence.
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by [email protected] » Tue Dec 20, 2016 2:49 pm
Poisson wrote:The most vexing problem faced by researchers exploring wind-powered generation of electricity is achieving a constant flow of power from an unpredictable natural source that meets demand, but so the flow does not overload electrical grids with sudden voltage increases

A. achieving a constant flow of power from an unpred-ictable natural source that meets demand, but so the flow does not overload
B. achieving a constant flow of power from an unpredictable natural source, which meets demand but without overloading
C. how to achieve a constant flow of power from an unpredictable natural source, a flow that meets demand but does not overload
D. how to achieve a constant flow of power from an unpredictable natural source, but a flow that meets demand without overloading
E. how a constant flow of power from an unpredictable natural source can be achieved, which meets demand but does not overload

The correct answer C seems odd to me because of the 'Independent Clause COMMA Dependent Clause' structure:

The most vexing problem faced by researchers exploring wind-powered generation of electricity is how to achieve a constant flow of power from an unpredictable natural source is an independent clause

Then there's a comma, followed by a dependent clause

Could someone please shed light onto the usage of this structure?

It's seems odd because I'm more familiar with the Independent Clause, "FANBOYS" Independent Clause structure.

Thanks so much

Source: GMATPREP Exam Question
When it comes to the ways we can combine clauses, English is incredibly flexible. Consider this sentence:

Tim is a nice guy, and he likes to cook. This is an example of what you mentioned: a FANBOY conjunction connecting two independent clauses.

But I could also express the same idea this way: Tim, who is a nice guy, likes to cook. Now we've got: subject, relative clause, predicate. But notice that the modifier in the middle, which I called a "relative clause," could also be referred to as a subordinate clause. (It's got a subject and a verb, and it's clearly subordinate to the main clause, "Tim is a nice guy.")

And if I'm tempted to cram a little more info into the sentence I could write, Tim, a nice guy who buys excellent presents for his neighbors, likes to cook. This is the construction Marty wrote about. "A nice guy" is an appositive that modifies Tim. Notice that you've still got a clause as part of the modifier ("who buys excellent presents"), but there's so many different ways we can work with clauses in a sentence that it doesn't make sense to memorize all of them. The main thing is to understand the logic of the sentence and the placement of the modifiers with respect to what they should modify.
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answer

by abhinavkgp » Tue Sep 04, 2018 2:47 pm
Poisson wrote:The most vexing problem faced by researchers exploring wind-powered generation of electricity is achieving a constant flow of power from an unpredictable natural source that meets demand, but so the flow does not overload electrical grids with sudden voltage increases

A. achieving a constant flow of power from an unpredictable natural source that meets demand, but so the flow does not overload
B. achieving a constant flow of power from an unpredictable natural source, which meets demand but without overloading
C. how to achieve a constant flow of power from an unpredictable natural source, a flow that meets demand but does not overload
D. how to achieve a constant flow of power from an unpredictable natural source, but a flow that meets demand without overloading
E. how a constant flow of power from an unpredictable natural source can be achieved, which meets demand but does not overload

Source: GMATPREP Exam Question
Hey Brent,

Can you please help me to answer my query?

How can we eliminate choice A? In a couple of forums, it is mentioned that 'that' refers to 'unpredictable natural source ', but I believe it could also refer to 'a constant flow of power' since there are a couple of cases in OG, where a noun modifier can refer to a faraway noun.

Also in B, assuming that 'which' can also modify 'flow', if the choice contained a comma between 'demand' and 'but', then I believe the choice will be grammatically parallel 'achieving a constant flow of power from an unpredictable natural source'|| but 'without overloading.......'. and will probably correct? Is there any major error which I missed?

Thanks,
Regards,
Abhinav

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by vietnam47 » Tue Aug 20, 2019 6:31 am
regarding A and B
achieving is similar to achievement. so, problem can not be achievement logically. " the problem is how to achieve " is logical

my problem is the victory on gmat
this is non logical similarly.