Logical reasoning PrepTest 149 · Section 3 · Question 14

Incorrect. There's no discussion of smaller carnivores, so this answer is out of scope.

Incorrect. While we can infer that the T-rex ate other T-rexes, we don't know if this was a common occurrence amongst carnivores. We don't even know if it was common amongst T-rexes—the discovered fossils could be outliers! (For example, they could have been from a period of food shortages.)

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:

(1) Marks on T-rex skeleton:

- Made by large carnivore
- Either from combat or feeding
- Almost impossible to be made on live animals

(2) T-rex only large carnivore in area at time

Answer Anticipation:
This stimulus features a lot of very strong statements ("only", "only", "only", "almost impossible"). These statements could be diagrammed using conditional logic, but they don't neatly chain together, so we're more going to need to analyze them for inferences rather than use a "clean" conditional process.

Looking at overlap between the statements, we can see that the marks on the skeletons were made by a large carnivore, and that the only animal fitting that bill is the T-rex itself, so these marks must have been made by other T-rexes.

Also, they were made either in combat or during feeding, but it's "almost impossible" that these marks would have been made on live animals. That rules out combat and leaves feeding as the action that resulted in these marks on the skeletons.

So the marks must have been made while a T-rex was feeding on a dead T-rex, so let's find that answer.

Answer Explanation:
This answer reflects the inference we could make by combining the strong, overlapping statements. T-rex was the only carnivore who could have left those marks, and they were made to a dead animal, so it must have been during feeding and not fighting.

Key Takeaway:
Even if strong statements don't neatly chain together using our conditional notation, we can still look for inferences by identifying overlapping statements.

Incorrect. While the argument raises combat as a possible source of the marks, it also notes that they almost certainly couldn't have been made to a living animal, effectively ruling that option out.

Incorrect. The argument doesn't discuss other continents or large carnivores that lived elsewhere, so this answer is out of scope.