Logical Reasoning

PT143 · S4 · Q17 Near many cities, contamination

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Near many cities, contamination of lakes and rivers from pollutants in rainwater runoff exceeds that from industrial discharge.

Conclusion (Thus)

Water itself is among the biggest water polluters.

Evidence

Contamination of lakes and rivers from pollutants in rainwater runoff exceeds that from industrial discharge.

As runoff washes over building and pavements, it picks up oil and other pollutants.

Evaluate

It's very unusual to see the main conclusion as the final claim, when we're doing Role or Main Conclusion (but it still happens 10% of the time).

The first two sentences both help support the last sentence. The 2nd sentence explains how it is that water pollutes at all. The 1st sentence supports the comparison that water is one of the biggest polluters by telling us that water outranks industrial discharge when it comes to contaminating lakes and rivers.

Goal

They're asking us about the first sentence. We would call it part of the Support. Is it just an unsupported premise or is it a supported intermediate conclusion?

Let's wait to worry about that if an answer choice makes us.

17.

The statement that contamination of lakes and rivers from pollutants in rainwater runoff exceeds that from industrial discharge plays which one of the following roles in the argument?

  1. It is a conclusion for

    Reversed Roles

    It makes more sense to say the 1st sentence supports the 3rd, than to say that the 3rd supports the 1st, as this answer is claiming. We can ask ourselves which of these feels better: Why should I believe that ... "Contamination of lakes and rivers from pollutants in rainwater runoff exceeds that from industrial discharge"? Because -- water itself is among the biggest water polluters. or Why should I believe that ... "Water itself is among the biggest water polluters"? Because -- Contamination of lakes and rivers from pollutants in rainwater runoff exceeds that from industrial discharge. The 2nd one feels more natural. The fact that pollutants from rainwater runoff exceeds pollutants from industrial discharge sounds like support for the idea that water is among the biggest polluters.

    2% picked this

  2. It is cited as evidence

    Bad Conclusion Match

    It is definitely evidence, but the conclusion is the final sentence: "water is among the biggest water polluters". According to this answer, the conclusion is some imaginary claim never said that "rainwater runoff is a more serious problem than industrial discharge".

    7% picked this

  3. It is a generalization based

    Weak Match

    Is tough to pinpoint the precise reason this is wrong. The 2nd sentence definitely helps us to understand how rainwater runoff could be a source of pollutants, but it feels wrong to say that a scientific measurement of whether pollutants from rainwater exceed that from industrial discharge is based on the observation that runoff picks up pollutants. Such a measurement would be based on actually tallying up types / amounts of pollutants. The 2nd sentence gives us the causal mechanism by which to understand how the 1st sentence could be true, but the 1st sentence isn't based off that observation.

    5% picked this

  4. Correct

    It is a premise offered

    Why this is right

    Well, this is just straightforward and pure. We can't argue with the fact that it's a premise (intermediate conclusions are also premises), and we can't argue with the fact that the conclusion was the final sentence. Where we might have to work hard to make other answers work, this one requires no work.

    Skill tested: Role · how this choice captures the argument's function is the move to repeat next time.

    85% picked this

  5. It is stated to provide

    Wrong Purpose

    It was not stated for the sake of providing a typical kind of city pollution. It was stated to support the comparative conclusion that water is one of the biggest polluters.

    1% picked this

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