PrepTest 144

Correct. Argument or Facts:
Argument

Valid or Flawed:
Valid

Question Type:
Parallel Reasoning

Stimulus Summary:
Wednesday-most-Kate buys guava juice
Buy guava juice → Local health food store
Therefore: Wednesday-some-Kate shops at local health food store

Answer Anticipation:
This argument features conditionals and quantifiers to a heavy degree. While not all of the terms are 100% the same from statement to statement, they do overlap enough that we can see if they validly chain together. (For instance, the term "Kate buys guava juice" doesn't overlap perfectly with the sufficient condition of the conditional, but that term is about everyone, including Kate, so she triggers it by buying guava juice.)

Looking at the quantifiers, we know that a most statement can be combined with a conditional to form an inference. Here, the overlapping terms—buying guava juice—are in the correct position to allow an inference to be drawn, and so the argument is valid (you never have to check if a some statement is stronger than the valid inference, as all inferences are at least some statements).

We need an answer that follows the same pattern, and we'll quickly eliminate any answer that doesn't have a conditional and most premise, and a some conclusion:

A-most-B
B → C
Therefore: A-some-C

(Note: It would be valid to conclude that Kate shops at the local health food store most Wednesdays, but it's not a flaw to conclude a weaker statement than is valid, just a stronger one.)

Answer Explanation:
Use main kitchen → Teacher at Institute
Dinner at Delice-most-Use main kitchen
Therefore: Dinner at Delice-some-Prepped by teacher at Institute

This follows the same pattern of reasoning as the stimulus, so this is our answer right off the bat!

Key Takeaway:
These harder Parallel Reasoning questions tend to have more answers that parallel the easily identifiable elements of the stimulus, especially when conditionals and quantified statements are involved. First, it's fine to skip this and come back when you know how much time you have—this is easily a 2+ minute question. Second, eliminate answers as soon as you see the relationships aren't the same—don't keep diagramming just to be complete. And if you find an answer early on that you like and you know you're behind on the clock, this is the one place where we'd recommend moving on and coming back to check the others only if you have time remaining.

Incorrect. This answer has two conditional premises and a conditional conclusion, so it isn't parallel.

Incorrect. Dinner at Delice-most-Prepped in Institute's kitchen
Teacher at Institute → Allowed to use kitchen
Eliminate this answer at this point—the shared term is on the wrong side of the conditional arrow (and taking the contrapositive will negate it).

Incorrect. Teacher at Institute-most-Allowed to use kitchen
Dinner at Delice → Prepped in Institute's kitchen
Similar to (C), we can eliminate this answer now as the shared term isn't in parallel positions to the stimulus.

Incorrect. Allowed to use Institute's kitchen → Teacher at Institute
Dinner at Delice-most-Prepared by teacher at Institute
And we can eliminate this answer at this point, as the shared terms from the premises aren't parallel to the stimulus.