LSAT 108 | Section 3 | Logical Reasoning: Q18

LR Question 18 Explanation

QUESTION TEXT: Chelas and Stelma are required to leave their respective stations …

QUESTION TYPE: Must Be False

FACTS:

1. If a prisoner attempts to escape, Chelas and Stelma must leave immediately to pursue.
2. If they aren’t pursuing an escaping prisoner, they can’t leave before replacements arrive.
3. Replacements arrived at 9PM.
4. Chelas violated the rules.
5. Stelma did not violate the rules.

ANALYSIS: Think of the rules like this:

Before 9PM, each person has only two acceptable options:

• Stay at the station if there’s no escape.
• Leave immediately if there is an escape.

Stelma didn’t violate the rules, so any answer where Stelma clearly violates the above two options is impossible.

___________

1. Both could be at their stations at 9PM. Chelas may have violated the rules earlier and returned by 9.
2. Stelma left before 9PM and Chelas didn’t. This could happen if a prisoner tried to escape and Stelma properly left to pursue, while Chelas wrongly stayed behind. So Chelas violated, Stelma didn’t.
3. Chelas left before 9 PM and Stelma didn’t. This could happen if there was no escape and Chelas improperly left his station. Stelma stayed, so she didn’t violate.
4. CORRECT. A prisoner tried to escape at 7PM, and neither Chelas nor Stelma left before 9PM. But if there was an escape, both were required to leave immediately. So both would have violated the rules, but that contradicts the fact that Stelma did not violate the rules.
5. A prisoner tried to escape at 7PM, and both left before 9 PM. This could still fit if Stelma left immediately, but Chelas left too late. So Stelma complied, while Chelas violated.