Logical reasoning PrepTest 129 · Section 3 · Question 17

Incorrect. This answer is more about how it functions, not whether it functions. It's also about selling an item in the first place, not refunding something that breaks.

Incorrect. The argument's timeline is only over the first 24 hours after purchase, so there's no need to assume that they can be expected to work "for about the same length of time."

Incorrect. The stimulus is about a product that broke within 24 hours. This answer is too broad in discussing customer expectations—sure, customers expect items they purchase to not break within 24 hours, but they also probably have other expectations that are out of scope of this argument.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
Department store: Buy watch AND Use as intended AND Breaks next day → Refund
I bought a watch from Bingham's (not a department store) and it broke the next day.
Therefore: Bingham's should give me a refund

Answer Anticipation:
That first conditional sets up quite a few sufficient conditions needed to get a refund! When it applies it to the specific scenario at hand, however, it ignores multiple sufficient conditions.

First, it ignores the sufficient condition of being a department store. The Consumer even notes that Bingham's isn't a department store. Therefore, the argument is relying on the assumption that Bingham's should be governed by the same refund policy as a department store.

Second, it ignores the sufficient condition that the watch has to be used as intended. The Consumer doesn't note whether she used that watch in any unintended ways. In order for this watch from Bingham's to be eligible for a refund (under the department store policy, as we addressed above), then it must have been used as intended.

Luckily, the Consumer does establish the third sufficient condition—the watch did break the very next day.

Since all three of the sufficient conditions are necessary ("AND") for this argument to work, the correct answer will establish at least one of the two missing conditions.

Answer Explanation:
This answer choice establishes one of the two missing sufficient conditions—and since there's only one conditional rule, those conditions are necessary for the conclusion to hold. If the consumer did use the watch in a way it wasn't intended, then the return policy she outlines wouldn't apply and the argument falls apart.

Key Takeaway:
When an argument relies on the application of a conditional to justify the conclusion, and there's only the one conditional given, then the application must establish the sufficient conditions. Yes, it's a bit of a weird situation that the sufficient conditions become necessary for the argument to work, but without establishing them, there's no other means of reaching the conclusion!

Incorrect. The stimulus doesn't state that the refund rules only apply to new watches, so this answer isn't necessary for the argument to work.