PrepTest 113

[lcid:3551] Prep Test 113 LSAT — Logical Reasoning — S4 Logical reasoning

Question prompt

The druid stones discovered Remaining source text redacted.
Why the credited answer is right

Credited answer: E

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

Druid stones in Ireland - Very old
This stone - In Scotland
Conclusion - This stone is not very old

Answer Anticipation

The argument establishes that all discovered druid stones in one location - Ireland - are very old. It then brings up a druid stone that isn’t in that location (it’s in Scotland), and it concludes that the stone isn’t very old.
While this argument doesn’t feature conditional logic, it is essentially committing an illegal negation. All Irish druid stones are old, so druid stones that aren’t Irish aren’t old. Let’s find an answer reflecting that.

Answer choices

  1. A
    allows a key term Remaining source text redacted.
    Why choice A is not credited
    The only terms that repeat are “discovered” and “druid stones,” and neither of them is used in a particularly odd way that would suggest the meaning shifted between use.
  2. B
    takes the fact that Remaining source text redacted.
    Why choice B is not credited
    First, there’s no mention of “most” of a group. Second, the argument doesn’t say that all of any group has a property - it says that one specific thing not in a group doesn’t have a property common to that group.
  3. C
    takes for granted the Remaining source text redacted.
    Why choice C is not credited
    This answer describes a Circular Reasoning flaw. However, the premise and conclusion are different here (a premise about Irish stones and one about the location of another stone; a conclusion about the age of that other stone), so it’s not circular.
  4. D
    presumes without justification that Remaining source text redacted.
    Why choice D is not credited
    While this answer does describe a Temporal flaw, it doesn’t apply here. First, because it talks about the current age, not what the age will be in the future. Second, because if something is old, that’s not going to change in the future. (Though if something is young now, it might be old in the future.)
  5. E
    takes the fact that Remaining source text redacted.
    Why choice E matches the stem
    This answer reflects the illegal negation we noted. It takes the fact that all Irish druid stones are old to constitute evidence that the Irish druid stones are the only old druid stones (i.e., a Scottish druid stone must be younger).

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