Q17 - Near many cities, contamination of lakes

[tamwaiman]

I consider the conclusion is the last sentence, and the first sentence is a intermediate conclusion explained by the second. However, I don't know why (C) is incorrect, can someone help to clarify? Thank you.

[ManhattanPrepLSAT1]

So I'm not a big fan of this question, since it seems really close, but to answer this one correctly, you need to ask yourself, "does the second sentence support the first?" My initial read says, "yes." But on closer inspection and with careful attention to answer choice (C) I think we can get to the correct answer.

Answer choice (C) says that it is a generalization based on an observation. Is the claim that "rainwater runoff collects pollutants on the way to the lakes and rivers" an observation from which a broader generalization that "contamination from rainwater runoff exceeds that from industrial discharge" is drawn? The answer the answer is, not really. The first sentence is a relative comparison. The second just supports that there is contamination from rainwater runoff, but not that it exceeds the contamination from industrial discharge. And for that reason we should not consider the second sentence an intermediate conclusion - eliminating answer choice (C) and forcing us to answer choice (D). The most useful word here for me was "generalization" in answer choice (C). A generalization is typically a broader claim that what happens specifically, also happens more generally. So I'd be looking for the first and second sentence to have a much more similar claim than is presented.

Let's look at the other answer choices:

(A) has the relationship backwards. It is supporting the last sentence, not being supported by it.
(B) is not true. The seriousness of the problem is never stated.
(C) is wrong for the reasons above.
(E) is not true. There is no suggestion that this is a representative form of other kinds of city pollution.

Hope that helps, and let me know if you have further questions on this one!

[ttunden]

So I'm not a big fan of this question, since it seems really close, but to answer this one correctly, you need to ask yourself, "does the second sentence support the first?" My initial read says, "yes." But on closer inspection and with careful attention to answer choice (C) I think we can get to the correct answer.

Answer choice (C) says that it is a generalization based on an observation. Is the claim that "rainwater runoff collects pollutants on the way to the lakes and rivers" an observation from which a broader generalization that "contamination from rainwater runoff exceeds that from industrial discharge" is drawn? The answer the answer is, not really. The first sentence is a relative comparison. The second just supports that there is contamination from rainwater runoff, but not that it exceeds the contamination from industrial discharge. And for that reason we should not consider the second sentence an intermediate conclusion - eliminating answer choice (C) and forcing us to answer choice (D). The most useful word here for me was "generalization" in answer choice (C). A generalization is typically a broader claim that what happens specifically, also happens more generally. So I'd be looking for the first and second sentence to have a much more similar claim than is presented.

Let's look at the other answer choices:

(A) has the relationship backwards. It is supporting the last sentence, not being supported by it.
(B) is not true. The seriousness of the problem is never stated.
(C) is wrong for the reasons above.
(E) is not true. There is no suggestion that this is a representative form of other kinds of city pollution.

Hope that helps, and let me know if you have further questions on this one!

I will add more about B

You can make an argument saying that it is a more serious problem due to the nature of the argument and the conclusion.

However, B is wrong in stating that the statement acts as evidence that pollution is more serious. What the statement really does is, support the conclusion that water is among the biggest water polluters.

I also didn't like how it was cited as evidence, since the statement the question stem is referencing contains something that is very similar to that stated in B. Ultimately, B is wrong because it misses the big picture of what that statement plays in the argument.

My explanation for the rest

A - This is not the conclusion of the argument. The conclusion is the last sentence, indicated by the THUS

C - reasons stated in the quote are good enough. to add further, it is not based on that observation. No indication it is based on the observation at all.

E - not an example of a TYPICAL kind of city pollution. Author never heads in this direction and doesn't say this is typical or frequent of a city.

If you need any further explanation, feel free to message me.

[lsat2016]

Hi!

Could anyone provide more explanation as to why D is the correct answer choice?
I didn't understand how the first sentence could be a premise (provide support) for the conclusion because it doesn't directly contribute to the ida that "water is among the biggest water polluters".

[ohthatpatrick]

The conclusion is that water is among the biggest water polluters.

If we only had the 2nd sentence for support, we would only conclude that "water IS a water polluter."

But the 1st sentence is the fact that provides support for the idea of "biggest". Water contaminates more than industrial discharge does?! Whoa.

If you were trying to convince me that water itself is a big water polluter,
you be telling me HOW it pollutes with the 2nd sentence
and telling me THE EXTENT TO WHICH it pollutes with the 1st sentence.

So both thoughts contribute to the claim that water is a big water polluter.

[lsat2016]

Hello,

Could anyone highlight the difference between a generalization and a conclusion?
What would have made the conclusion stated in the stimulus into a generalization?

[LolaC289]

Actually, I don't think there is a strict "supporting" relationship between the first sentence and the second, since the first sentence is a comparative statement. The second sentence only provided information on how can the rainwater runoff become water polluter itself (by washing over buildings and pavements and picking up pollutants). But as far as it is concerned, the comparison to industrial pollution is not mentioned. Thus, it is not appropriate to say the first sentence is a "generalization" based on the observation that the second sentence provided, since the "exceeds that from industrial discharge" part is obviously beyond the scope of the second sentence. We can't generalize something that's not even mentioned.

The structure: the second sentence --(partial support/evidence)--> the first sentence ---(support/premise/evidence)--> the last sentence (main conclusion)

[ldfdsa]

I got this wrong during timed test.

The frist sentence tells us contamination from pollutants in runoff exceeds that from industrial discharge, which is a fact.

The second sentence does not support the 1st sentense at all. It gives us more reason to support the conclusion, the last sentence, by telling us that: when runoff (already more contaminated from pollutants than from industrial discharge) washes over buildings, it becomes even more contaminated.