Logical reasoning PrepTest 125 · Section 4 · Question 9

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen (Principle)

Stimulus Summary:
Background - A phone book published the Jacksons' number as Sara's, and they keep getting calls for her. Sara gave the Jacksons her correct number.
Details - The Jacksons made no promises, but it'd be helpful if they passed her number along.
Judgment - 1) It's not wrong for them to not pass on number; 2) It'd be laudable if they did pass it along.

Answer Anticipation:
Strengthen (Principle) questions task us with finding an answer that justifies the judgment drawn in the conclusion based on the details in the premises. Here, there are two judgments in the conclusion, so we should work backwards to see what details presented are likely to be used to justify each of them:
Judgment 1 - It wouldn't be wrong for the Jacksons to fail to pass Sara's number on
Judgment 2 - It would be laudable for them to pass her number along

And the details really boil down to two key ones:
Detail 1 - The Jacksons didn't promise Sara they'd pass her number on
Detail 2 - It'd be helpful for the Jacksons to pass Sara's number along

Trying to "match" the relevant detail to each judgment, we can see that Detail 1 will likely be used to justify Judgment 1. First, it doesn't make sense to say it'd be helpful to do something, so it's not wrong to not do it. Second, it not being wrong does seem to be at least somewhat justified by them making no promises.

The analysis for Detail 2 likely supporting Judgment 2 uses the same logic, to arrive at the same place—the helpful nature of passing the number along is likely going to justify the conclusion that it'd be laudable to do it.

So we want an answer that reflects both of these connections:
If you don't make a promise to do something, it's not wrong to fail to do it, but it's laudable to do something helpful.

Answer Explanation:
This answer addresses both of the judgments made in the conclusion of the stimulus, so we should dive in to see if it justifies that conclusion. The first half justifies Judgment 2 based on Detail 2, so that half is covered by this principle. And the second, in setting up a necessary condition for an action to be wrong (Wrong to fail to do something → Promised to do it) allows us, through the contrapositive to justify the conclusion that it's not wrong for the Jacksons to fail to pass on Sara's number since they made no promises they would. This answer, therefore, fully justifies the conclusion and is correct.

Key Takeaway:
Strengthen (Principle) questions task us with finding an answer that connects details from the premises to the judgments in the conclusion. Be sure to clearly outline the likely justification for each judgment in the conclusion and to not conflate them when you look at the answer choices!

Incorrect. This answer has an action not being wrong as a sufficient condition, not a necessary condition. Since the conclusion features the judgment about the action not being wrong, this answer doesn't align with the argument.

Incorrect. So close! This answer feels as if it justifies both parts of the conclusion (even though it only relies on one detail). However, there's a subtle reason this is wrong. It talks about a helpful action someone can take—in this case, that's passing on the phone number. This answer justifies passing the number along as laudable and not wrong; the conclusion states that passing the number along is laudable but not passing it along is not wrong. Since this answer doesn't establish anything about not passing the number along, it's incorrect.

Incorrect. Similar to (C), this answer doesn't address the conclusion about not passing the number along. It also sets out difficulty as a necessary condition for an action being laudable, and passing the number along isn't difficult.

Incorrect. This answer establishes a necessary condition for an action to be laudable, so it can't justify a conclusion that an action is laudable.