PrepTest 113

Incorrect. The opening premise here isn't really conditional, nor does it bring up subjective knowledge, so this answer can be eliminated.

Incorrect. The premises have the elements we're looking for here, but the conclusion is about what "may" never happen, not what's "unlikely" to happen, so we can eliminate it.

Incorrect. This answer has all the elements we identified on a quick read, so we need to diagram it out to see if the terms relate in the right way:
Animal known to live in Scrag Island lagoon → Frogs
Scrag Island owl diet → Frogs on island
And we can hop out now, as the shared term here is the frogs, and they're both in the necessary condition. In the stimulus, the shared term—tanzanite—was in the sufficient condition of one conditional and the necessary condition of the other.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Parallel Reasoning

Stimulus Summary:
Known deposit of tanzanite → Tanzania
Stone Ashley collects → Tanzanite
Conclusion - Ashley probably won't collect a stone that's not from Tanzania

Answer Anticipation:
As with all Parallel Reasoning questions, we should identify the relevant logical features so we can find answers that match up with them.

Here, we start with a conditional premise ("All"). However, it's important to note there's a relevant detail in these conditions—it talks about "known" deposits of tanzanite. This leaves open the possibility that there are other deposits that we don't know about. Whenever an LSAT question brings up subjective knowledge, it's relevant to the logic and we should be sure to pay attention.

After we get that conditional premise, we get a second conditional premise ("only"). If you didn't view this as a conditional, that's fine as long as you noted the "only" in there, as we need a premise that has similar strength to it.

That second premise relates to the sufficient condition of the first one, but they're not directly connected to each other. The argument, however, applies the conditional while making it a bit less certain ("unlikely"). (To see how it applies the conditional, we can rephrase the conclusion to be "It's likely that Ashley will collect stones only from Tanzania.")

Let's find an answer that follows the same pattern and has the same elements we identified.

Answer Explanation:
This answer also has all the elements we identified on a quick read, so we need to diagram it out to see if the terms relate in the right way:
Discovered Scrag Island frog → Lagoon
Scrag Island owl diet → Frogs on island
Conclusion - Scrag Island owls will probably never eat an animal outside the lagoon
The elements all line up in the right places with the stimulus, so this is the correct answer.

Key Takeaway:
Knowing what elements are relevant to the logic of arguments on the LSAT is unbelievably helpful in all question types, as it lets you quickly home in on the relevant areas. For Parallel Reasoning questions, this can save you a lot of time when you can eliminate an answer that's missing one of these elements.

Incorrect. The opening premise doesn't have information about subjective knowledge, and the conclusion is certain instead of about what is unlikely, so we can eliminate this answer.