PrepTest 125

[lcid:3597] Prep Test 125 LSAT — Logical Reasoning — S2 Logical reasoning

Question prompt

There are 1.3 billion Remaining source text redacted.
Why the credited answer is right

Credited answer: A

The notes below walk through why it fits the stem and how to eliminate the rest.

Question Type

Strengthen Questions

Answer choices

  1. A
    Cows given good–quality diets Remaining source text redacted.
    Why choice A matches the stem
    Correct. Argument or Facts:
    Argument

    Valid or Flawed:
    Flawed

    Question Type:
    Strengthen

    Stimulus Summary:
    Cow population - 1.3b and growing to meet demand
    Cows cause methane, which causes global warming
    Most cows are fed low-quality food, but they produce less methane when eating wellTherefore - If cows were fed well, then they would produce less methane

    Answer Anticipation:
    Comparisons and causality—two common elements that we should explore in this stimulus!

    Here, the argument has causal premises, so we shouldn't expect a correlation/causation flaw. The premises establish that a bad diet causes cows to produce methane, which causes global warming. It also compares this causal relationship to what happens when you feed cows a good diet—they still produce methane, but less of it.

    From that, the argument concludes that switching cows to a quality diet will keep methane in check. While it's unclear what that means (stabilize it? lower it? keep it within suggested guidelines?), it at the very least means that cows won't be releasing as much methane as they would otherwise, which is another comparison.

    However, this argument falls into a very common trap on the LSAT, generally when making a prediction about what impact a change would have. While it establishes that the methane release per cow would go down on a high quality diet, it doesn't establish that nothing else relevant would change that would counteract that decrease in methane per cow. Maybe growing the high-quality feed would produce more methane than it would save. Maybe cows on a high-quality diet produce less meat or milk, thus necessitating more cows. Any answer that rules out another effect of switching to a high-quality diet that would increase methane released will strengthen this argument.

    Answer Explanation:
    This answer highlights that the suggested change won't have a negative impact on the driving factors behind cow population growth. If better feed results in both fewer cows needed to meet demand and less methane per cow, then that change should, in fact, lower the amount of methane released compared to the current trend.

    Key Takeaway:
    Whenever the argument makes a prediction about the effects of a change, consider what else might change as a result. The argument usually misses some other effect that could counteract whatever effect it notes.
  2. B
    Carbon and hydrogen, the Remaining source text redacted.
    Why choice B is not credited
    Incorrect. This answer is too science-y, trying to get you to think about how digestion works and how chemicals play into that. Regardless, the argument establishes that less methane is produced by cows on a high-quality diet, so this answer about elements is out of scope.
  3. C
    Most farmers would be Remaining source text redacted.
    Why choice C is not credited
    Incorrect. The viability of this plan and associated cost is out of scope. The conclusion is conditioned on the diets being changed, so it doesn't matter if that can or will happen.
  4. D
    Worldwide, more methane is Remaining source text redacted.
    Why choice D is not credited
    Incorrect. The argument lumps these two considerations together and never splits them up, so this answer doesn't affect the argument. If it had compared the production of meat and milk on different diets, then this answer might have been a consideration.
  5. E
    Per liter, methane contributes Remaining source text redacted.
    Why choice E is not credited
    Incorrect. The conclusion is limited to discussing the impact on methane production, not global warming, and carbon dioxide is never mentioned. Since CO2 isn't mentioned and it's out of scope of the conclusion, this answer is out of scope. If the conclusion were about global warming, then this answer might be relevant in establishing the relative importance of methane.

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