Installing scrubbers in smokestacks and switching to cleaner-burning

Conclusion: By installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants.

Jolt down in mind some of the assumptions on which argument based:
1. [Assumption can serve to fill in a logic gap.] Scrubbers will reduce the harmful emissions
2. [Assumption can serve to fill in a logic gap.] Clean fuel reduce the harmful emissions
3. [Assumption can establish the feasibility of the premises of the argument] Scrubbers will reduce harmful emissions more than the cleaner-burning fuel.
4. [Assumption can eliminate alternate path to the same end] There is no better alternative way for the Northern Power to reduce the most of the harmful emissions than to install scrubbers.

Now, let check the answer choices that closely matches with our mental argument assumption dump (I mean our list)

(A)Switching to cleaner-burning fuel will not be more expensive than installing scrubbers. [This argument is not about Northern Power’s expensive/inexpensive mode installing scrubbers – Eliminate it]
(B)Northern Power can choose from among various Kinds of scrubbers, some of which are more effective than others. [This argument is not about list of scrubbers choices that Northern Power has – Eliminate it]
(C)Northern Power is not necessarily committed to reducing harmful emissions from its plants. [Contradicts the conclusion – Eliminate it]
(D)Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone. [This sounds close to our mental assumption 4 – hold it]
(E)Aside from harmful emissions from the smokestacks of its plants, the activities of Northern Power do not cause significant air pollution. [Definitely not interested in Northern Power’s day to day business – Eliminate it]

Answer: D

+1

Agree with D here. Just a bit detailed explanation...

It is really a good technique to use negating test on assumptions questions. Ask yourself what if the proposed assumption is not true..? Apply to each answer choice until you find the one that make the argument fall apart. Here is an example of how it works
e.g. Let's take the answer choice "D":
Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone. But if this is not true, and Harmful emissions can be reduced more by using both methods together, then the conclusion does not make much sense any more: "Therefore, by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants",.. because "they will be doing the most.." by using both methods together.. So they have to assume that using both methods will not be any better than just installing scrubbers.

This logic works every time for assumption questions.

D. The argument assumes that both cannot be used at the same time. If this were true, then Northern Power would not be doing everything it can, thus the argument falls apart.

Scrubbers and fuel are two methods to reduce harm emissions. Scrubbers are more effective than fuel.
Hence by installing scrubbers company is doing the most it can do to reduce emissions.

The argument clearly assumes that xyz is the best way to reduce emissions. Assuming that no other way is better. That is combined effect is not better.
Choices are
A -- $ aspect is out of scope
B -- might be true and strengthen the concl, but not necessary for it to follow. Even if all scrubbers are equally effective, the combined effect can be more effective. Also, the more effective scrubbers combined with fuel can be still more effective.
C -- Out of scope. If anything it weakens the conclusion
D -- Correct choice as mentioned earlier
E -- Out of scope. The argument does not deal with whether the cumulative emissions of NP are low or high.

Often, the argument jumps to a conclusion without filling in the gap. In this argument, the author states that Scrubbers will reduce harmful emissions better than the other approach. Then, it jumps to conclude that, Scrubbers will be doing the MOST of what can be done...

Obviously the assumption is there is no better alternative than Scrubbers...

(A) the cost is irrelevant...
(B) different scrubbers... fine, fine but that this doesn't show why the author jumps to conclusion and believe that the most that can be done is the Scrubbers
(C) their commitment is irrelevant...
(D) if combination of the two methods produce far better results than Scrubbers alone then the conclusion will be invalid.. hence, this needs to be assumed...
(E) the sources of emissions is irrelevant...

Answer: D

Hi,

This is an assumption that you can come up with before going to answer choices. Having a good grip on the "story" of the questions is critical. Sometimes it helps to paraphrase: There's a power company. They can have ONLY two options for creating cleaner emissions: clean fuel or filters. Filters do more than clean fuel. Therefore for max clean they should choose filters.

We were never told that the choices are mutually exclusive. Maybe we can choose both. It is important NOT to add anything or lose anything from the story. It is very easy to add the idea of exclusivity because in our normal lives we make many decisions based on the idea that you can't have both (you choose one movie, one apartment, one entree...) but on the GMAT options are not mutually exclusive unless we are told so.

Happy Studies,

HG.

Premise: Scrubbers will reduce harmful emissions more than cleaner-burning fuels will
Conclusion: by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions

Assumption: Scrubbers and cleaner-burning working together cannot reduce more than each method working alone.
Negation technique: If both methods working together reduces more than each method working alone. The conclusion is broken.

D is correct.

Conclusion: by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants
premise: Scrubbers will reduce harmfull emission more than cleaner-burning fuels will.

Assumption: 1) Cleaner fuel will not reduce the harmful emission as Scrubbers
2) Installing scrubbers is the only way for Northern power to reduce the emission and they dont have any other way to reduce.


(A)Switching to cleaner-burning fuel will not be more expensive than installing scrubbers. - Out of scope - Expensive is not in play now
(B)Northern Power can choose from among various Kinds of scrubbers, some of which are more effective than others. - Out of scope - Various kind of scrubbers is not an issue
(C)Northern Power is not necessarily committed to reducing harmful emissions from its plants. - Breaks the conclusion directly
(D)Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone. - seems to be more in align with our assumption 2. Negating this choice breaks the conclusion.
(E)Aside from harmful emissions from the smokestacks of its plants, the activities of Northern Power do not cause significant air pollution - Irrelevant to our conclusion


Press kudos if this helped.

Regards,
Swami.

There is a causality in the conclusion. Installing Scrubber will do the most. Nothing else will do the same is the assumption or eliminating the case where any factor else can do the most is another way of framing the assumption. Choice D just does that.

Installing scrubbers in smokestacks and switching to cleaner-burning fuel are the two methods available to Northern Power for reducing harmful emissions from its plants. – A background information.
Scrubbers will reduce harmful emissions more than cleaner-burning fuels will. – A background information.

Therefore, by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants. - Conclusion derived from the two informations provided above.

So are all options evaluated ? What are the assumptions for this conclusion?

In how many ways we can select the solution to reduce harmful emissions from its plants -
1) by installing scrubbers in smokestacks
2) by switching to cleaner-burning fuel – rejected as mentioned in the premise.
3) by using both of them – no information provided in the argument.
Hence, if the conclusion is that option1 is the best then it can be assumed that option3 is not better than option1.
Assumption – there is no other better option.

(A)Switching to cleaner-burning fuel will not be more expensive than installing scrubbers. – not discussed in the argument.
(B)Northern Power can choose from among various Kinds of scrubbers, some of which are more effective than others. - – beyond the discussion .
(C)Northern Power is not necessarily committed to reducing harmful emissions from its plants. – no information to suggest so – not discussed in the argument.
(D)Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone. – Correct
(E) Aside from harmful emissions from the smokestacks of its plants, the activities of Northern Power do not cause significant air pollution. - not discussed in the argument.

Argument say that by installing scrubbers, company would be doing the most that it can do.

(A) This is quite close. HOLD.
(B) This is not a relevant point. OUT
(C) The argument mentions that Northern Power is taking steps to reduce emissions. So this is not an assumption. OUT
(D) This is the precise assumption that invalidates the conclusion. Why cant Northern Power use both options? If we negate this argument - Suppose both methods can be used, and still Northern Power is not using them, then it is trying to economize and is NOT doing its utmost. This is a better choice than A.
(E)Issue is of harmful emission, so this is an irrelevant point.

THE CORRECT ANSWER IS D
We have to find the ASSUMPTION on which the argument rest

Let us first break the argument into Premise and Conclusion.
Premise 1) Scrubber and clean fuel will reduce harmful gases
Premise 2) Scrubber will reduce more harmful gases
Premise 3)- ASSUMTIONS (which is a unstated premise but which is a must for reaching conclusion.. we have to find it)
Conclusion)-Northern Power will do its maximum effort by installing only Scrubber to reduce harmful gases

DO U SEE THE GAP IN REASONING
Scrubbers are not the maximum effort to reduce harmful gas. It can be further reduces by using clean fuels. (see premise 1)
SO the argument is assuming that maximum reduction can be achieved by only scrubbers but it forgets that clean fuel will further reduce the harmful gases

SO the correct answer will be one will tell us that NORTHERN POWER has assumed that both scrubber and fuel cannot both reduce harmful gases even more than scrubber alone.
WHAT OPTIONS SAYS THAT:-

(D)Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone.

THE CORRECT ANSWER IS D

Installing scrubbers in smokestacks and switching to cleaner-burning fuel are the two methods available to Northern Power for reducing harmful emissions from its plants. Scrubbers will reduce harmful emissions more than cleaner-burning fuels will. Therefore, by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants.
Scrubber > Cleaner burning fuel

Which of the following is an assumption on which the argument depends?

(A)Switching to cleaner-burning fuel will not be more expensive than installing scrubbers.
We ain't talking about the cost of both the products.

(B)Northern Power can choose from among various Kinds of scrubbers, some of which are more effective than others.
Again we have to compare scrubbers with cleaner burning fuel and not to other scrubbers.

(C)Northern Power is not necessarily committed to reducing harmful emissions from its plants.
We are again not concerned about the intension. And this assumption is actually going against the conclusion.

(D)Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone.
They assumed that both cannot be together and that is why kept only scrubber in their plant.

(E)Aside from harmful emissions from the smokestacks of its plants, the activities of Northern Power do not cause significant air pollution
A tempting answer. But we need to see the diffrence. Premise talks about pollution control from its plants and this answer option is concerned about the totality of the pollution.

The argument is that Northern Power will be doing the most it can to reduce harmful emissions if it installs scrubbers.
This is supported by the following premises:
Premise: Scrubbers will reduce emissions more than cleaner fuel will.
Premise: emissions can be reduced by installing scrubbers or switching to cleaner fuel

Given the premises and the decisive conclusion, the gap in logic here is that combining the two methods will not yield greater reductions in emissions than one method alone. (This is a supporter assumption as we are coordinating evidence with the decision made in the conclusion)

A - the cost of switching is irrelevant to the argument that NP will be doing the most it can to reduce emissions
B - The types of scrubbers are irrelevant to the argument that NP will be doing the most it can to reduce emissions
C - NP's committment is irrelevant to the argument that NP will be doing the most it can to reduce emissions
D - Correct as it supports the conclusion.
E - This is out of scope of the argument.

Conclusion: “by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants”
Prethink: is there NOTHING else NP can be doing? “Most” is pretty extreme. What if it used both? What if there’s another alternative that is better because of some recent innovations?
Which of the following is an assumption on which the argument depends?

(A) Switching to cleaner-burning fuel will not be more expensive than installing scrubbers.
Out of scope – we don’t care about the price. We need to focus on the conclusion: by installing scrubbers, NP will be doing the MOST that can be done to reduce harmful emissions from its plants. Regardless, whether it’s expensive or not, as long as NP is doing the MOST it’s good. This can be true or false and the argument is still good.

(B) Northern Power can choose from among various kinds of scrubbers, some of which are more effective than others.
Out of scope trap – effectiveness doesn’t matter – presumably, they’re talking about effectiveness to clean. We don’t care about this. We want to know if they’re doing the most to reduce harmful emissions from its plants.

(C) Northern Power is not necessarily committed to reducing harmful emissions from its plants.
Out of scope trap – we don’t care about what NP is committed to. So long as NP is doing the most that can be done with these scrubbers, NP is all good.

(D) Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone.
Okay this is an assumption. We’re assuming within the stimulus that using the scrubbers ALONE is the best option. But what if they use both? Would it help a little less than 2x as much? This shows that it is not the case. The stimulus assumes this is true to show that the conclusion is true. Defender answer choice. Matches prethink as well.

(E) Aside from harmful emissions from the smokestacks of its plants, the activities of Northern Power do not cause significant air pollution.
Out of scope – it doesn’t matter what activities cause “significant air pollution.” All we need to know is that the scrubbers is the best option to use to do the MOST to reduce harmful emissions from its plants.

Installing scrubbers in smokestacks and switching to cleaner-burning fuel are the two methods available to Northern Power for reducing harmful emissions from its plants. Scrubbers will reduce harmful emissions more than cleaner-burning fuels will. Therefore, by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants.

Which of the following is an assumption on which the argument depends?

(A)Switching to cleaner-burning fuel will not be more expensive than installing scrubbers--- [color=#ffff00]We are not concerned about the costs here.[/color]
(B)Northern Power can choose from among various Kinds of scrubbers, some of which are more effective than others.----[color=#ffff00]Kinds of scrubbers are totally irrelevant.[/color]
(C)Northern Power is not necessarily committed to reducing harmful emissions from its plants---[color=#ffff00]Irrelevant. Argument is concerned with methods to reduce emissions.[/color]
(D)Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone---[color=#ffff00]Please find below the explanation for this.[/color]
(E)Aside from harmful emissions from the smokestacks of its plants, the activities of Northern Power do not cause significant air pollution.----[color=#ffff00]Out of scope. We are not concerned with something other than the harmful emissions.[/color]

-- [color=#ffff00]Focus on the word "most" in the conclusion of the argument. The conclusion says that by installing the scrubbers only, Northern Power will be doing the most that can be done to reduce the harmful emissions.
What if we say that more can be done (reduction in emissions) by using both the methods together? The negation of option D just does that.
By negating option D, we get that emissions can be reduced more by using both the methods than by the installation of scrubbers alone. This breaks the conclusion.[/color]

Installing scrubbers in smokestacks and switching to cleaner-burning fuel are the two methods available to Northern Power for reducing harmful emissions from its plants. Scrubbers will reduce harmful emissions more than cleaner-burning fuels will. Therefore, by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants.

Which of the following is an assumption on which the argument depends?

(A) Switching to cleaner-burning fuel will not be more expensive than installing scrubbers.
-cost is irrelevant

(B) Northern Power can choose from among various kinds of scrubbers, some of which are more effective than others.
-this seems to strengthen the argument …not the same as an assumption

(C) Northern Power is not necessarily committed to reducing harmful emissions from its plants.
-this weakens the argument…why would Northern Power ‘be doing the most that can be done’ if it does not care

(D) Harmful emissions from Northern Power's plants cannot be reduced more by using both methods together than by the installation of scrubbers alone.
-Correct…if this were untrue, then there is another using both methods would DO MORE to reduce emissions and importantly, we know as well that both methods are available to Northern Power.

(E) Aside from harmful emissions from the smokestacks of its plants, the activities of Northern Power do not cause significant air pollution.
-irrelevant
_________________

Can someone explain why E is not correct.

If Aside from harmful emissions from the smokestacks of its plants, there are other activities of Northern Power that cause significant air pollution, then installing scrubbers may not work. Right:?? Am I missing something here?

The argument begins with the following statement:

Installing scrubbers in smokestacks and switching to cleaner-burning fuel are the two methods available to Northern Power for reducing harmful emissions from its plants.

Then, the conclusion is the following:

by installing scrubbers, Northern Power will be doing the most that can be done to reduce harmful emissions from its plants.

We see that the argument is about doing the most that can be done with regard to one goal, "reducing harmful emissions from its plants."

So, even if (E) is not true and OTHER activities of Northern Power DO cause significant air pollution, it could still be the case that, by installing scrubbers, Northern Power will be "doing the most that can be done to reduce harmful emissions from its plants" specifically.