PrepTest 107

[lcid:3524] Prep Test 107 LSAT — Logical Reasoning — S1 Logical reasoning

Question prompt

In Debbie's magic act, 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.

Argument or Facts

Argument

Valid or Flawed

Flawed

Question Type

Errors in Reasoning Questions

Stimulus Summary

Debbie does a magic trick, and a skeptic tried to explain it.
Trial 1 - Trick recorded (no sleight of hand)
Trial 2 - The skeptic provided a deck of cards (no trick deck)
Trial 3 - The skeptic picked the card (no audience plant)
Conclusion - Debbie doesn’t use sleight of hand, trick decks, or a plant for her trick

Answer Anticipation

In this argument, the Skeptic is attempting to figure out how Debbie performs her magic trick. He sets up three experiments in order to test out different theories.
The first trial was to see if Debbie uses sleight of hand, and the videotape shows that she didn’t. The second trial was to see if she uses a trick deck, but that was ruled out in that trial. And finally, the Skeptic tested whether a plant in the audience was used by Debbie, and one wasn’t in that third trial.
So where’s the flaw? Didn’t the Skeptic rule out the three methods that Debbie could use? Well, he ruled out those methods in the individual trials where he was looking for them, but he never tested out all three at the same time! Maybe Debbie has different ways of doing the trick, and she rotated to avoid detection by the Skeptic in each trial.

Answer choices

  1. A
    The skeptic failed to Remaining source text redacted.
    Why choice A matches the stem
    This answer reflects the possibility the Skeptic overlooked. He ruled out one method at a time, failing to consider that Debbie was rotating through methods of achieving her trick.
  2. B
    The skeptic failed to Remaining source text redacted.
    Why choice B is not credited
    As long as videotaping Debbie would detect sleight of hand, it doesn’t matter if there are other methods of detection that would be effective, as well.
  3. C
    The skeptic failed to Remaining source text redacted.
    Why choice C is not credited
    If she requires both of those methods, then the first and second trials should both have prevented her from pulling off the trick. Since she was successful, both methods can’t be required.
  4. D
    The skeptic failed to Remaining source text redacted.
    Why choice D is not credited
    The Skeptic doesn’t believe Debbie is doing literal magic, so he very much believes that she’s using some method other than one of these three to achieve her effect.
  5. E
    The skeptic failed to Remaining source text redacted.
    Why choice E is not credited
    The Skeptic does believe that it was intentional and not a coincidence, he just hasn’t yet figured out what method she’s using to achieve the effect.

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