PrepTest 152

Incorrect. The If portion of the conclusion in this answer matches up with the first half of the Most statement in this answer, so it doesn't feature the same reversal.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
Pet owner AND Allergy meds-most-Allergic to pets
Chuck has a pet
Therefore: Chuck develops allergy to pet → Likely take allergy meds

Answer Anticipation:
This stimulus has conditionals and quantifiers all over the place, and they're a bit of a mess—they're almost certainly related to the flaw. Digging in a bit deeper, the issue here is that the argument reverses that "most" statement, which is an invalid inference. (If you had diagrammed the conclusion as "Chuck develops allergy to pet-most-Take allergy meds," there's nothing necessarily wrong with that—the important thing is that you noted the "likely" in some way.)

Unfortunately, only one answer choice doesn't match up with the "most" premise and conditional conclusion with a "likely" in it! We'll have to go through each answer choice and see if it matches up with that reversal. Instead of diagramming each out, to save some time, let's see if we can make some eliminations based on a read-through—a good thing to look for is the If portion of the conclusion matching up with the second half of the Most statement.

Answer Explanation:
The If portion of this conclusion matches with the second half of the Most statement, so we should diagram this to see if it matches:
Car taken to Acme-most-Electrical problem
Therefore: Electrical problems → Likely car taken to Acme
This answer features the same reversal! Note that we don't need every aspect to match up in a Flawed Parallel Reasoning question, just the flaw—and that flaw here was the reversal of the Most statement. This is our answer.

Key Takeaway:
Two takeaways. First, in Flawed Parallel Reasoning questions, only the elements related to the flaw need to match up. That's different from Parallel Reasoning questions. Here, noting that the flaw was the reversal of the Most statement let us select an answer that didn't have the exact same structure as the stimulus but still had a Most statement that was reversed.

Second, when all or most of the answers don't have features that let you quickly eliminate them, try to identify a specific thing that must match up in the answers—like here, where we set a strategy of comparing the If part of the conclusion to the second half of the Most statement. This can save you some time as you can skip a few diagrams.

Incorrect. The If part of the conclusion is the negation of the second half of the Most statement, so we can eliminate it. This answer tries to take the contrapositive of a Most statement, which isn't valid.

Incorrect. That "unlikely" is enough to throw out this answer choice since every other answer matches the "likely" of the stimulus. This is, sadly, the only "easy" elimination!

Incorrect. This answer reverses the Most statement . . . but it has an issue not present in the stimulus. The conclusion is about what Anastasia will do when she "thinks" the car has electrical problems, which is a key shift away from the stimulus that hints at a second flaw (perception vs. reality or subjective vs. objective) not present there.