Logical reasoning PrepTest 151 · Section 3 · Question 12

Incorrect. This argument deals in facts, not beliefs, so this answer about which paleontologists believed something is out of scope.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Sufficient Premise

Stimulus Summary:
A fossil is evidence of X only if it's all from one animal. This fossil is from all over the discover site, so it's not evidence of X.

Answer Anticipation:
A conditional rule is given:
Fossil is evidence → From one animal
The conclusion is that the fossil isn't evidence, so the contrapositive is more useful:
Not from one animal → Fossil isn't evidence

To reach the conclusion, the argument needs to establish that the fossil isn't from one animal. Instead, it establishes that the bones are from all over the discovery site. It's possible the fossil of a single animal ended up spread out in one area, either through predation or natural forces over the millions of years since the dino died.

Answer Explanation:
Here's our answer. The argument establishes that the fossil is a composite. If that's sufficient to mean it's from more than one animal, the conditional in the argument triggers and the conclusion is valid.

Key Takeaway:
Strengthen with Sufficient Premise questions will frequently provide an argument with a conditional rule that isn't triggered. Instead, it will present a piece of information that seems related to the trigger—the correct answer will directly relate the known information to the sufficient condition of the conditional.

Incorrect. The conclusion of this argument is about a particular fossil being evidence of a theory, so other pieces of evidence are out of scope.

Incorrect. The argument never discusses well-preserved specimens, so this answer is out of scope. This answer also mentions the entire fossil being from the same animal, which isn't established in the argument (in fact, it's assume that it isn't).

Incorrect. It belongs in a museum! The history of this fossil is out of scope to determining if it's from one or more than one dinosaur.