Logical reasoning PrepTest 118 · Section 4 · Question 19

Incorrect. First, bold prescriptions are probably called for if there is a high probability of a disastrous event. Second, calling for funding into research is hardly a bold prescription.

Incorrect. This answer is, without a doubt, trying to get you to get confused and wrapped up in math/probability terminology. It sounds smart, and the topic is confusing, so it's probably right! Wrong. These answers are almost always traps. Here, the event in question—a meteorite strike—is expected to happen soon, so there's no completed time period yet during which it was expected to occur.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Earth is hit by a meteorite once every 100m years, and the last was 100m years ago, so we'll be hit soon and should see if we can protect ourselves.

Answer Anticipation:
First, the main point here—that we should look into protecting ourselves from an imminent and catastrophic meteorite strike—is valid if the premises are accepted. It's actually a pretty tame conclusion in the face of the apocalypse—it's essentially saying we should fund some research.

Since that main point is justified based on the premises, the gap in the logic must be between the premises and the intermediate conclusion. Looking there, we can see a common flaw on the LSAT—making a prediction about the future based on what has happened in the past. The argument bases a prediction that presents a rather limited range—a meteorite will strike "in the near future"—on past events that have a very wide range—meteorite strikes occur about once every 100m years. If there's a 10m year variance there—sometimes a strike happens after 90m years, other times 110m years—then we could still be 10m years away from a meteorite strike. If that's the case, then we've got some time.

The correct answer should highlight this jump to a conclusion predicting impending doom based on past trends that are wide-ranging.

Answer Explanation:
This answer highlights the jump in the argument. A meteorite strike occurs about once every 100m years. That's an average taken over the lifetime of the planet. It can't be used to make a specific prediction about when the next event will occur—it can only speak to the probability of it happening based on the likelihood of the trend continuing.

Key Takeaway:
Any argument that makes a prediction is likely doing so based on past events or trends. Whenever you see a prediction in the conclusion, start thinking along these lines.

Incorrect. The argument references ice ages to discuss the size of the meteorite, not the actual effect once it hits. Even if a meteorite of that size doesn't cause an ice age, it's probably going to do some major damage. Additionally, it's rare that the specific likelihood of something occurring will need to be established on an argument in the LSAT.

Incorrect. The conclusion is about investing in research to determine whether there is a means to protect Earth from such a meteorite strike, so it doesn't assume that there is.