PrepTest 105

[lcid:3517] Prep Test 105 LSAT — Logical Reasoning — S2 Logical reasoning

Question prompt

Premiums for automobile accident Remaining source text redacted.
Why the credited answer is right

Credited answer: C

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

Argument or Facts

Argument

Valid or Flawed

Flawed

Question Type

Errors in Reasoning Questions

Stimulus Summary

Insurance companies: Red cars are in more likely to be in an accident than cars of other colors Author: If true, then we can save lives by banning red cars

Answer Anticipation

As with all Errors in Reasoning questions, we should be reading to identify elements that are commonly involved with flawed logic. But before we get into that, we should note that the conclusion has an important element - it’s qualified. The author bases her conclusion on the claim by the insurance companies being correct - that a greater percentage of red cars are in accidents than any other color. So there’s no flaw associated with supporting that detail - the conclusion is based on it being true. So with that out of the way, do we have any commonly flawed elements? Well, the conclusion claims that making a certain change would have a given effect. When that’s the case, the conclusion is causal, so we should figure out what the author believes is the cause and effect here. The recommended change is banning red cars, so the author must believe that they’re the cause of something. And the effect is saving lives. What mechanism would allow this to save lives? Reducing accidents. So the author’s conclusion is based on the assumption that red cars cause accidents. When an argument has a causal conclusion, it’s generally flawed because it jumps between correlation and causation. So is the premise here a correlation? It is - a “greater percentage” of red cars get into accidents than cars of any other color. Or, in other words, red cars are correlated with accidents. There’s no discussion of this being causal! There could be another cause - say, reckless drivers prefer red cars and also cause more accidents. Since this argument jumps from a correlation to causation, the correct answer should reflect that common error in reasoning.

Answer choices

  1. A
    accepts without question that Remaining source text redacted.
    Why choice A is not credited
    The conclusion is about saving lives, not insurance. The author pivots away from the discussion of insurance premiums, so this answer is out of scope.
  2. B
    fails to consider whether Remaining source text redacted.
    Why choice B is not credited
    The conclusion is about saving lives, not the cost of repairs, so this answer is out of scope.
  3. C
    ignores the possibility that Remaining source text redacted.
    Why choice C matches the stem
    This answer highlights the possibility that there is a cause of both correlated phenomena that could explain the correlation (and one that we anticipated). If reckless drivers prefer red cars, then banning red cars would just put those drivers in other cars without reducing their recklessness. This answer is a common one in Errors in Reasoning questions with a Correlation/Causation flaw - it brings up an alternative cause for both the supposed cause and effect.
  4. D
    does not specify precisely Remaining source text redacted.
    Why choice D is not credited
    The specific percentage doesn’t matter - what matters is that there’s a correlation there, and a stronger one than between other colors and accidents. Whether 60% or 40% of red cars get into accidents, that could be higher than, say, the 10% of green cars that are.
  5. E
    makes an unsupported assumption Remaining source text redacted.
    Why choice E is not credited
    The argument assumes only that there are enough fatal accidents that lowering the accident rate would prevent some fatalities, thus saving some lives.

What this tests

Discussion

  • A 0 replies

    Started by bihaoqing@gmail.com

  • Why is E wrong? 3 replies

    Started by SarahA