Logical reasoning PrepTest 149 · Section 1 · Question 25

Incorrect. The premises are both conditional, so we can rule this answer out without diagramming it.

Incorrect. Student AND PA thinks work is greatly improved → High grade
Student-some-High grade . . . and we can jump out. To run parallel to the stimulus, this premise would have to talk about students who don't receive high grades.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Valid

Question Type:
Parallel Reasoning

Stimulus Summary:
Popular AND Groundbreaking → Critically acclaimed
Popular-some-not Critically acclaimed
Therefore Ð Popular-some-not Groundbreaking

Answer Anticipation:
This argument uses a less common means of drawing an inference from a conditional and a quantified statement, but it is valid. If you want to dig into it, take the contrapositive of the conditional, and you'll see that you can validly combine it with the some statement.

But that doesn't really matter for a Parallel Reasoning question! We just need to match up the structure. If you properly diagrammed the some statement ("Not all do" is equivalent to saying "Some don't"), you be ready to go:

A AND B → C
A-some-not C
Therefore Ð A-some-not B

Answer Explanation:
Biography AND Unbiased → Embarrassing facts
Biography-some-not Embarrassing facts
Therefore Ð Biography-some-Unbiased
Same pattern of reasoning, so this is our answer.

Key Takeaway:
If you have a clear conditional structure (including quantifiers) in the stimulus of a Parallel Reasoning question, there's no need to analyze the logic. It can be good to do during review, but any answer that follows the same conditional structure will follow the same logic.

Incorrect. This argument doesn't have a some premise, just two conditionals, so it's incorrect.

Incorrect. Book AND Worth reading → Worth buying
Book-some-not Worth reading . . . and we can eliminate this answer. The other term in this some premise should be not Worth buying to be parallel to the stimulus.