Logical reasoning PrepTest 119 · Section 4 · Question 11

Correct. Argument or Facts:
Facts

Question Type:
Strengthen

Stimulus Summary:
Hypothesis - South America's east coast was once attached to Africa's west coast

Answer Anticipation:
This stimulus sets out a theory (continental drift), but it asks about a hypothesis related to that theory. Specifically, the hypothesis that South American used to be attached to Africa.

We're tasked with finding an answer that supports that hypothesis, but there really aren't any premises provided for it. So we can head into the answers looking for anything that connects the two areas. Any similarity between them will serve to support the hypothesis that they were once connected.

Note that we should also anticipate a specific type of trap answer. Since the argument talks about the east coast of South America and the west coast of Africa, let's make sure we don't pick an answer that reverses those. While it's not certain that they'll go that route to try to trap us, they have in the past, so we need to be careful.

Answer Explanation:
This answer establishes a similarity between the two regions in question that represents a rare type of rock—meaning that the similarity is unlikely to be a coincidence. As such, this answer strengthens the hypothesis.

Key Takeaway:
Note answers (B) and (D)—they were two answers that are tempting, but they're wrong for the same reason. These types of "paired" answers can be good for double-eliminations, as you'll frequently be presented with two answers that are wrong for the same reasons! Don't be shy about eliminating a second answer for reasons that you've already highlighted for another—there are plenty of examples on the LSAT of two answers being similarly wrong.

Incorrect. First, there's no indication that people aren't all genetically quite similar to each other! Second, this isn't related to the land—it's related to people. Since no timeline is established for the breakup of the supercontinent, it's possible that it happened before humans evolved.

Incorrect. Climate isn't related to the land being attached—it has to do with location on the planet more than anything.

Incorrect. This answer is similar to (B) in that it deals with people instead of the land, and so there are many other explanations for the similarities other than the land being previously connected.

Incorrect. This answer doesn't mention that the plants in South America grow on the east coast, so it doesn't support the hypothesis. It also doesn't establish that this is a rarity—maybe most plants resemble each other.