Recently implemented "shift-work equations" based on studies of the hu

Dear R26, I guess you mean the comma after the word “job”. When I look at the sentence, it seems not to be underlined. However, I don’t think you need to worry about this comma. The equations have reduced three things. The second and third thing must be separated by “and”. Whether there is a comma there or not doesn’t matter. Eliminate A, B and D. As mentioned, “was lowered” in E is redundant. Choose C. Fortunately, the GMAT is not a test of punctuation!

The sentence is in two parallel parts. The first part says "shift-work equations" has 1."reduced sickness", 2. "sleeping on the job",and 3."fatigue.". The second part of the sentence is the result of 1,2, and 3 which is raising production efficiency. Hence raising is the result of these three actions. Hence it should be in " ing " form. The answer therefore cannot be "B" and is "C."

I know it changes the meaning, but would a sentence like this be correct?

Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping on the job, fatigue among shift workers, and production efficiency in various industries.

Honestly I can't understand the rule used to arrive to choice C... There seem to be 10 different opinions and I couldn't see a solid rule that could be applied in all cases (99% of cases)

Can we have a list with, say 10 elements? "I like 1,2,3,4,5,6,7,8,9, and 10" ? There is no limit to the number of elements in a list, since they are all parallel, right?

Another one, somebody used this way to see it and this one does make sense to be a solid rule:

Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, have reduced sleeping on the job, have reduced fatigue among shift workers, and have reduced have raised production efficiency in various industries. -> Wrong, doesn't make sense, need to change.

Is this way to analyse it correct?

Thank you!

To say that this sentence changes the meaning, would be too mild. This sentence is actually not making any sense. This is suggesting that recently implemented "shift-work equations" have reduced four things:

i) sickness
ii) sleeping on the job,
iii) fatigue among shift workers and
iv) production efficiency

The reason this does not make sense, is because if sickness, sleeping, and fatigue are reduced, there is no reason why production efficiency should also reduce.

Absolutely. In fact, our book EducationAisle Sentence Correction Nirvana discusses the parallelism philosophy through a simplified XYZ deconstruct, its application and examples in significant detail. If someone is interested, PM me your email-id, I can mail the corresponding section.

yes, yes I understand it makes no sense, but for example purposes, imagine that it does make sense for some reason, then the list would be correct? Is there a limit to the number of elements you can list? No, right?..
But it seems that on Gmat they like to use "1,2 and 3"-lists, so 3elements in parallel and then something else happens.

Let's make the example sentence more logical:

Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping on the job, fatigue among shift workers, and labor accidents in various industries. -> would this be correct? Here I don't like the (comma)-And formation, wouldn't it require an Independent clause? I'm a bit confused with this...

And good to know that the XYZ analysis works. Its good to have a checker-rule!

Thank you.

Correct.

Yes.

It's just a list (more than 2 elements), and hence, there is a comma. Another officially correct sentence:

Twenty-two feet long and 10 feet in diameter, the AM-1 is one of the many new satellites that are part of a 15-year effort to subject the interactions of Earth's atmosphere, ocean, and land surfaces to detailed scrutiny from space.

Notice the comma before and land surfaces.

Having said that, the presence or absence of comma before and should not be a reason for you to select/ignore an option.

One question. Raising is not parallel with have reduced. I think the correct answer would have been: and fatigue among shift workers while they have raised...

Am I right???

Consider "while" not as a parallelism marker, but as a contrast marker.

Consider the sentence this way:

Independent clause, present participle modifier (modifying the entire clause preceding it):
Equations have reduced fatigue, (while) raising the efficiency.

Since the modification is to show a contrast, "while" is added before the present participle.

Since this is an official question, it can be inferred that GMAC accepts such use of "while", though I do agree that the sentence you have mentioned is better.

GMATNinja , egmat , VeritasKarishma , MartyMurray

I am finding it difficult to accept C as the answer choice. As per my understanding, "while" is a subordinator and required a bonafide verb which is clearly missing here in option C. Can anybody please help me understand?

"While" can be used in two ways.

It can be used to start a clause. In such cases "while" is similar to "whereas," and the clause so begun is a subordinate clause.

"While" can also be used to convey, simply, "at the same time", without the connotations of the word "whereas." When used in this way, "while" can be used to begin a clause, but what follows "while" that means "at the same time" does not have to be a clause.

Consider the following examples:

"While" Begins Clause: While the guests were enjoying the sunset, the band set up.

The above sentence conveys that the band set up as the guests were enjoying the sunset.

"While" Without Clause: While setting up, the band members discussed the song list.

This above sentence conveys that, as they were setting up, the band members discussed the song list.

"While Without Clause: My uncle Harry would sing opera while skiing in the Alps.

Notice, in this last sentence, there is no comma before "while". When "while" means "when", you don't need a comma before it. When "while" means "whereas" and begins a clause, the clause has to be separated from the rest of the sentence by a comma.

Here's another example without a comma:

We ran around town while our parents were shopping for bicycles.

The fact that "while" is not preceded by a comma confirms that, in this case, it does not mean "whereas".

An adverb clause can be reduced to an adverbial phrase if it has the same subject as the main clause.

While I was skiing, I saw ...
is same as
While skiing, I saw ...

It reflects that the two happened "at the same time".


Recently implemented "shift-work equations" ... have reduced A, B, and C while raising production efficiency ...

is same as

Recently implemented "shift-work equations" ... have reduced A, B, and C while they are raising production efficiency ...

AjiteshArun GMATNinja,

I have a questions here.
Need support to eliminate option A. I am not satisfied with mentioned answers.

Hi Harsh2111s,

Let's take a look at the list:

Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced
(a) sickness,
(b) sleeping on the job,
(c) fatigue among shift workers,
and
(d) have raised production efficiency

The first three are nouns, and make sense with have reduced (have reduced sickness, have reduced sleeping, have reduced fatigue), but after that, we run into a verb phrase (have raised...) instead of a noun, and we end up with have reduced have raised production efficiency as the final element in the list.

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But I think have is used to make things parallel.
Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping......,fatigue.....(have reduced sickness, have reduced sleeping, have reduced fatigue))and

Recently implemented "shift-work equations" based on studies of the human sleep cycle have raised production efficiency.

Need some more input.

Hi Harsh2111s,

That's one way of looking at it, but then we'd really need two lists, which would in turn mean that we'd expect to see two conjunctions in the sentence.

Equations have reduced (X, Y, and Z), and have raised (B).

To see why it'd be much better to include the second conjunction, check if you'd be comfortable with the following sentence:

Equations have reduced X, Y, and have raised B.

Will it be correct if the sentence structure in A is as below

'have reduced X,Y and Z and have raised'

Can someone please clarify?

Hi NimishaKrishna,

Doing that would certainly remove that particular error, but it is hard to say whether option A would then be "correct". Generally, we should avoid evaluating altered options, because we'd then be going by our own opinions, instead of those of the GMAT.