Logical reasoning PrepTest 142 · Section 1 · Question 24

Incorrect. If Ted is incapable of reporting the accident, then he doesn't have to—and none of the other conditions matter. As such, we can't conclude this connection.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Driver in accident AND Driver capable of reporting AND (Personal injury OR Property damage over $500) → Legal requirement to report
Ted was a drive in an accident, but he's not legally required to report

Answer Anticipation:
What a complicated conditional statement! It has two necessary sufficient conditions, but one is an OR statement so it has two conditions each of which is equally sufficient to satisfy it . . . That was a complicated explanation, so let's take a step back.

When you have an exceptionally complex conditional statement, sometimes it's best to not try to diagram it all out. We've got the diagram here (and we'll include the contrapositive below so you can practice), but it might be best to just work through it slowly and reading it in plain English.

Let's start with Ted. Ted was a driver in an accident, so he meets that part of the sufficient condition. However, the stimulus also says that he doesn't need to report the accident, so he can't meet the other part(s) of the sufficient condition.

Looking at it, that part says that the accident either:

Results in personal injury, or

Results in property damage over $500

Since Ted didn't have to report the accident, it must be true that his accident doesn't satisfy either of these conditions . . . if Ted is capable of reporting the accident, which is the last wrinkle in this conditional statement. If Ted is incapable of reporting the incident, then he's not required to do so. If he is capable of reporting the incident, then we're back up to Ted's accident not meeting at least one of the above conditions.

Two things before moving on. First, whenever the LSAT has a condition based on a number, make sure you're precise with your understanding. Here, the condition is over $500—$500 exactly doesn't meet that condition.

Second, here's the contrapositive of the above:
not Require to report → not Driver in accident OR not Driver capable of reporting OR (not Personal injury AND not Property damage over $500)

Answer Explanation:
If Ted's car was damaged over $500, then this accident meets one of the conditions leading to a legal requirement to report. Since Ted was a driver, he meets a second condition to legally report. Since he doesn't need to legally report, he must not meet at least one of the sufficient conditions that creates that legal requirement to report, and the only one left is the "incapable of reporting" condition—so Ted must not be capable of reporting. This answer is supported by the stimulus.

Key Takeaway:
If you're rock solid at conditional logic, you can attempt to tackle a stimulus like this using formal notation. If you're not, though, work through it in plain English. Formal logic is a tool, and, like all tools, sometimes it's not the best one for the job.

Incorrect. Any driver involved in such an accident is required to report it if it meets the given conditions, barring being incapable of doing so. Since this answer doesn't establish that Ted is incapable of reporting the accident, this answer isn't supported.

Incorrect. The stimulus doesn't go into details about why someone might be incapable of reporting the accident, so we can't infer that it's because of injury.

Incorrect. This would be the answer if we knew that Ted is capable of reporting the accident. Without knowing that, however, we can't infer that the sufficient condition Ted doesn't meet is the one about injury or damage.