Logical Reasoning

PT109 · S1 · Q5 A recent national study of

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A recent national study of the trash discarded in several representative areas confirmed that plastics constitute a smaller proportion of all trash than paper products do, whether the trash is measured by weight or by volume.

Conclusion (therefore)

The current use of plastics actually does less harm to the environment nationwide than that of paper products.

Evidence

The environmental damage done by given unit of plastic trash is roughly the same as the damage done by an equal unit of paper trash.

A national survey shows there is currently less plastic trash than paper trash.

Evaluate

Usually, like 90% of the time, the conclusion on Main Conclusion questions is earlier than the evidence. But in this case it's the final claim, telegraphed with the indicator word "therefore".

The word 'therefore' is definitely signaling that the final sentence is a conclusion, but is it just an intermediate conclusion there to fool us?

No. The other two sentences aren't eligible to be conclusions, because they're both facts and there isn't any support offered for either one.

The last sentence is supported by combining the 1st and 2nd sentences.

P1: the harm caused by 1 unit of Plastic trash = 1 unit of Paper trash P2: nationwide, fewer units of trash are plastic than paper C: so, nationwide more harm is caused by plastic than paper

Goal

We're just looking for the answer whose meaning best matches the final claim,

They'll probably invert it or use synonyms, or both:

5.

The main conclusion of the argument is that

  1. plastics constitute a smaller proportion

    Premise

    This doesn't match the final sentence, which is about "harm". This is just about the "proportion". This is the 1st sentence, which was a factual, unsupported premise.

    6% picked this

  2. the ratio of weight to

    Out of Scope: ratio

    This doesn't match the final sentence, which is about "harm". This is talking about the ratio of weight to volume, which is totally out of scope.

    1% picked this

  3. popular opinion regards the use

    Unstated Inference

    This resembles the language of the final sentence, but the final claim is that "the current use of plastics does less harm than paper". This says, "People generally think that paper is less harmful than plastic." We can infer this answer choice, based on the "contrary to popular opinion" that comes right before the conclusion, but this is not the conclusion. This is the misconception that paper is less harmful. The conclusion is the reality, that plastic is less harmful.

    3% picked this

  4. contrary to popular opinion, a

    Unstated Out of Scope: shift away

    This doesn't match the final sentence, which is about "harm". This is about whether shifting away from paper would benefit the nation. That wasn't ever said, so it's not going match our explicit conclusion.

    9% picked this

  5. Correct

    at this time more harm

    Why this is right

    This matches the meaning of the final claim, which is the conclusion indicated by the word "therefore" currently, plastics do less harm to the environment nationwide than paper "at this time, more harm to the environment nationwide is done by paper than by plastic" As we guessed, they are trying to disguise this correct answer by re-wording the conclusion with an inversion. We know that 6 > 5 means the same thing as 5 < 6. So concluding "Plastic does less harm than paper" is equivalent to concluding that "paper does more harm".

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

    80% picked this

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