Logical reasoning PrepTest 130 · Section 4 · Question 13

Incorrect. There's no indication that the large and small frogs can't coexist in areas other than arid ones. Small frogs can't live in the arid areas, but both small and large frogs can live in the wet areas.

Incorrect. If anything, the argument suggests that the arid areas have only large adult frogs, whereas the wet areas have both large and small frogs, and therefore the arid areas would be more likely to have a higher average weight.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Adult frogs: Permeable skins make them subject to dehydration
Small frogs: Can't survive in arid climates
Large frogs: Can survive in arid climates ("Unlike large adult frogs . . . ")
Moisture requirements: Most important factor in where frogs can live
Yucatan: North is arid, south is wet

Answer Anticipation:
First, note the premise we highlighted about the large adult frogs—that they can survive in arid climates. This is an implication of the lead-in to the premise about small adult frogs not being able to survive in those climates—"Unlike large adult frogs." That introductory clause implies that whatever is said about the small ones doesn't apply to the large ones, as we noted in the summary.

With that said, this Must Be True question has a little bit of everything! Comparisons (between large and small adult frogs; between the north and south areas of Yucatan), strong criteria (moisture requirements are the "most important factor"), and strong statements/conditionals (Arid → not Small adult frogs survive). Each of these statements individually would be a potential factor in a correct answer, and since they all overlap in content, there's a good chance that making an inference that uses each of these statements will lead us to the correct answer.

Taking a look at those statements, we can see that moisture requirements are going to determine where these small and large adult frogs live, and the small ones can't live in arid climates—so they can't live in the north of the Yucatan. The large adult frogs, on the other hand, can live there. As for the south where it's wet, there's no indication that either sized frog can't survive in areas that have more moisture, since that's what they need to survive. The correct answer will likely bring these statements together.

Answer Explanation:
Large adult frogs, unlike small ones, can live in arid areas. Both frogs can presumably live in wet areas. That means the large frogs can live in both the north and south of the Yucatan peninsula, but the small ones can only live in the south, and thus this answer is supported.

Key Takeaway:
Comparisons, strong statements, criteria, and conditionals all tend to lead to correct answers in Must Be True questions. When you have a mix-and-match of all of them, and they all discuss the same concepts, there's a good chance that spending a few seconds to figure out how they all build together will allow you to form a pretty strong anticipation for the correct answer.

Incorrect. The populations of large and small adult frogs in an area where both can survive is never mentioned, so this answer is out of scope.

Incorrect. The stimulus states that small adult frogs can't survive in arid climates, and north Yucatan is noted as being arid, so there aren't any small adult frogs in the north and this answer is wrong.