Logical reasoning PrepTest 127 · Section 2 · Question 23

Incorrect. While the plentiful supply of this food is the reason that squirrel monkeys thrive in 2nd-growth forests, there's no indication that these supplies are only present in those forests. Maybe they're present in other habitats that are unsuitable for squirrel monkeys for other reasons—such as they're not even forests!

Incorrect. While this is a reversal of the conditional chain, it's a weak one ("At least some . . . "), and we can reverse conditionals if we make them weaker (e.g., if all lawyers are rich, then some rich people are lawyers). The biggest issue here is that it jumps from the conditional statements in the stimulus to a causal statement—the conservationists will intervene "by" preserving certain forests. Conditional statements can feel causal, but they're not—they establish correlations. Even if 2nd-growth forests being preserved guarantees that conservationists intervened, it doesn't mean that they intervened by preserving those forests—that's an improper jump from, again, conditional statements to causal ones.

Incorrect. While a plentiful supply of these food sources in 2nd-growth forests leads to the squirrel monkeys thriving, there's no indication that they are necessary for the monkeys to survive.

Incorrect. Intervention of conservationists → not Squirrel monkeys extinct. This answer is a reversal of a premise.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
not Intervention of conservationists → Squirrel monkeys extinct

Large amounts of 2nd-growth forest preserved → Squirrel monkeys survive2nd-growth forests have a lot of insects and fruits that squirrel monkey like

Answer Anticipation:
This Must Be True question features two conditional statements and a non-conditional statement, so let's start by seeing if they can be combined. While the statements as presented don't have a shared term, we can make two of the terms overlap—since an animal is either extinct or it has survived, we can say that the term "Squirrel monkeys survive" is the same as them not going extinct, and we can take the contrapositive so that the conditionals can chain together:

not Intervention of conservationists → Squirrel monkeys extinct → not Large amounts of 2nd-growth forest preserved

Large amounts of 2nd-growth forest preserved → not Squirrel monkeys extinct → Intervention of conservationists

We have an inference based on the conditionals, but can we work the non-conditional statement into it to get another inference? Not really. It provides a bit of an explanation as to why these forests are relevant to squirrel monkey survival, but it doesn't trigger a conditional or present any information that's strong enough to lead to an inference. Let's head to the answer choices to see if we can find something based on that chain!

Answer Explanation:
not Intervention of conservationists → not Large amounts of 2nd-growth forests preserved. This answer reflects the conditional chain that could be made from the two conditional premises, so this is our answer.

Key Takeaway:
Do NOT conflate conditional statements and causal ones! Conditional statements will sound causal, but they're only establishing a correlation. Without causal language included in the conditional statement (e.g., "If conservationists intervene by preserving forests, then that will lead to the squirrel monkey surviving."), conditional statements cannot support causal ones.