#17 - Near many cities, contamination of lakes and

[Administrator]

Complete Question Explanation

Method of Reasoning—AP. The correct answer choice is (D)

Method of Reasoning—Argument Part questions require you to understand the role of each element
in the stimulus to determine how they relate to statement in the question stem. The question stem
focuses on the role of the statement regarding excess runoff from industrial discharge in lakes and
rivers, but knowing what the other statements do will help you distinguish Losers and Contenders
among your answer choices.

You can usually apply the “Why” test to a statement in order to determine if it is a premise or a
conclusion. Nearly all conclusions will be explained elsewhere in the stimulus, while the majority of
premises will not (exceptions include intermediate conclusions, which have an explanation elsewhere
and also serve as premises for the main conclusion). In addition, conclusion or premise indicators
also define the role of a statement.

The last statement contains a conclusion indicator (“Thus”) and also passes the “Why” test. Why is
water itself among the biggest water polluters? Because contamination from rainwater runoff often
exceeds that from industrial discharge as runoff picks up oil and other pollutants. Since the other
statements in the stimulus both answer “Why” regarding the conclusion, they are each premises.

Answer choice (A): This is incorrect. The conclusion is that water itself should be considered a
polluter and this claim is offered as support of that conclusion.

Answer choice (B): The argument does not claim that pollution from rainwater runoff is a more
serious problem than pollution from industrial discharge; it only claims that rainwater contamination
exceeds contamination from industrial discharge.

Answer choice (C): This statement is not a generalization based on the observation of rainwater
picking up oil and other pollutants; it is a consequence of that observation. A generalization would
by definition expand the scope of the observation to some broader context, which does not occur
here.

Answer choice (D): This is the correct answer choice. This is the best description of the role
played by the statement indicated in the question stem.

Answer choice (E): The argument does not address typical kinds of city pollution and this statement
is not used as an example of anything. It is used to suggest that water itself can pollute water.

[hrhyoo]

Hi Powerscore,

I selected B and during blind review, I picked B again and I was very sure B is the correct answer. The conclusion claims that water is "the biggest" water polluters and to make such a superlative statement, you need to make comparisons and in this case the comparison between rainwater runoff and industrial discharge. Isn't that what B is saying? I rejected D because I thought B is the better answer choice. I am very confused.

Please help and thanks in advance.


Hanna

[KelseyWoods]

Hi Hanna!

Careful, here. The conclusion doesn't say that water is THE biggest water polluter; instead, it says that water is "AMONG the biggest water polluters." It's a subtle difference, but it's important. The argument is not that water is a bigger water polluter than any other source, just that water is one of the major water polluters.

Another subtlety to pay attention to in answer choice (B) is the idea of rainwater runoff being "a more serious problem than pollution from industrial discharge." The stimulus doesn't actually tell us that rainwater runoff is a "more serious problem." Rather, it says that "near many cities, contamination of lakes and rivers from pollutants in rainwater runoff exceeds that from industrial discharge." Just because the contamination from rainwater runoff exceeds contamination from industrial discharge in some cities, does not actually mean that rainwater runoff pollution is a more serious problem. Maybe the specific types of pollutants from industrial discharge make it more serious than rainwater runoff. Maybe industrial discharge is a more serious problem because it more often contaminates water in rural areas. We really don't know enough from this stimulus to determine if pollution rainwater runoff is a more serious problem than industrial discharge.

Hope this helps!

Best,
Kelsey

[hrhyoo]

Hi Kelsey,

Thank you for your responce. I understand your point of view but I still feel that B is better. I equated more contamination with a more serious problem since if rainwater conteminated wider areas than industrial dischage then you could think that rainwater presents a more serious problem than industrial discharge. More importantly, by giving such evidence that rainwater is worse than industrial discharge, which is probably different than what people may expect, it makes the conclusion more convincing.

I really want to think like the LSAT testmakers so I could improve my score. Please help me fix my way of thinking!


Hanna

[James Finch]

Hi Hanna,

One of the major things the LR section tests is how precise you are with language. When we have key terms that are necessary to a conclusion or a premise, we have to make sure that they are either present in a correct choice or synonyms that have the same exact meaning. Here, (B) is wrong because it fundamentally distorts the meaning of the conclusion: the conclusion in the stimulus is an absolute statement, essentially saying that rainwater is a major pollutant of bodies of water. What it isn't saying is that rainwater is a bigger pollutant than industrial pollution, which is a relative comparison, the opposite of an absolute statement. Be very careful as relative vs absolute is one of the key points tested on the LSAT, and being precise with language is the key to maintaining the same meaning from stimulus to answer choice. Only (D) does that here; both (B) and (D) correctly identify the noted sentence as a premise, but (B) mischaracterizes the conclusion into a relative comparison while (D) correctly characterizes the conclusion by using the exact same absolute language as is present in the stimulus's conclusion.

Hope this clears things up!

[hrhyoo]

Oooh, crystal clear now! Thank you so much, James!

H

[mseggio]

I'm not going to explain my detailed breakdown of this stimulus, as that would only be repetitive. However, after initially diagramming this, I thought that it was possible the text we were tasked to identify could be an intermediary conclusion?

This response was not supported by the answer choices, however if someone could correct me as to whether or not I am understanding the idea of an intermediary conclusion correctly...

Intermediary conclusion would be some piece of text that is not only a premise (offering support for a conclusion), but also a conclusion itself (which is not the main conclusion), and to identify it as an "intermediary" conclusion, it would have to be supported by something else?

Thanks!

[Rachael Wilkenfeld]

Exactly mseggio. An intermediate conclusion is both support for the main conclusion (and acting as a premise) and supported by other parts of the stimulus (and acting like a conclusion). I don't see this one as a intermediate conclusion though. Both premises here work together to support the main conclusion.

Here's an example of an argument with an intermediate conclusion.

Premise: All men are mortal.
Premise: Tom Brady is a man.
Intermediate conclusion: Tom Brady is mortal.
Premise: All mortals will not exist forever.
Conclusion: Tom Brady will not play football forever.

The intermediate conclusion is supported by the first two premises, and supports the ultimate conclusion. Each of the premises there, though, do not also serve as a conclusion. They work together to either support the main conclusion directly or support it through the intermediate conclusion.

Hope that helps!