PrepTest 106

[lcid:3520] Prep Test 106 LSAT — Logical Reasoning — S1 Logical reasoning

Question prompt

For any given ticket 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

Flawed Parallel Reasoning Questions

Stimulus Summary

Each lottery ticket will probably lose, so it’s reasonable that no one will win.

Answer Anticipation

We know that this is an invalid argument because, well, people win the lottery. But what is the flaw here?
Well, one way to look at it is this. What are the odds that a lottery ticket will win? 1/1000. But as you start to look at all the lottery tickets, the question isn’t whether a given one will win, but rather whether one of a lot of them will win. While the odds for an individual ticket is 1/1000, the odds for one out of, say, 2000 tickets winning is actually quite high (99.999999817%, if you’re curious)!
In other words, this argument is going from what is true of an individual ticket, to what is true of a group of tickets, making this a Part to Whole flaw. Let’s find an answer that makes the same jump.

Answer choices

  1. A
    It is reasonable to Remaining source text redacted.
    Why choice A matches the stem
    The odds of one card drawn being an ace is low, so you’ll never draw an ace. That’s the same jump from the odds in a single instance to the odds in a lot of instances, so this is the correct answer.
  2. B
    When the chances of Remaining source text redacted.
    Why choice B is not credited
    This argument’s conclusion restates the premise, only flipping it around. It’s also about something that’s statistically very likely to happen, not unlikely.
  3. C
    It is unreasonable to Remaining source text redacted.
    Why choice C is not credited
    This answer is similar to (B), in that the premise and conclusion more or less restate each other.
  4. D
    It is reasonable to Remaining source text redacted.
    Why choice D is not credited
    Another answer where the conclusion is more or less a restatement of the premise (since if a coin was flipped 1000 times and it was tails each time, then the last time it was flipped it was tails).
  5. E
    For any given group Remaining source text redacted.
    Why choice E is not credited
    This answer applies what is true of a group to an individual - that’s a Whole to Part jump, not a Part to Whole one.

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