LR Question 11 Explanation
QUESTION TEXT: John works five days each week except when on vacation…
QUESTION TYPE: Necessary Assumption
CONCLUSION: Last week, John must have worked as an insurance agent on Monday, Tuesday, Wednesday and Thursday.
REASONING: John works four days a week as an insurance agent and on Fridays he works as a Blacksmith. John works five days per week on weeks when there is no holiday and he takes no vacation. This week there were no holidays and John took no vacation.
ANALYSIS: The argument is assuming that John’s workweek is from Monday to Friday, i.e. that he didn’t work on the weekend. Without that, he could have done some insurance work on Saturday or Sunday, meaning he might not have worked Monday through Thursday. That would make the conclusion invalid.
___________
- This is irrelevant. John took no vacation this week.
- The stimulus doesn’t say whether John has to work full days or not.
- There are no vacations or holidays last week. Irrelevant.
- CORRECT. The argument didn’t say that John only works weekdays. We can only conclude that John worked Mon, Tues, Wed and Thursday if he didn’t work on the weekend last week.
- The argument never said that John works as a blacksmith only on Fridays. He could also work as a blacksmith on Tuesdays, for example, after he leaves work at the insurance office.
Every condition is met, John would still be working five days each week, four in an insurance office, and as a blacksmith on Fridays.
Recap: The question begins with “John works five days each week except when on vacation”. It is a Necessary Assumption question. Learn how to master LSAT Necessary questions on the LSAT Logical Reasoning question types page.
More Resources for Necessary Assumption Questions
- Negations Article: Learn about negations on the LSAT.
- Conditional Reasoning Article: Learn about conditional statements.
- Negations Drill: Practice your negation skills.
- LR Diagrams Guide: Learn how to draw LR diagrams.
- Intro to Conditional Reasoning: Learn conditional reasoning basics.
- Intro Course lesson: This intro course lesson covers Necessary Assumption questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers necessary assumption questions.
Doesn’t your reasoning for E actually show that that is a possiblity, and therefore we must assume it ISN’T a possibility? Otherwise we can demonstrate that the argument doesn’t logically follow – the argument says he “must”, not that he “could” have worked those days.
If we only assume D, then isn’t the exact situation you stated in E still possible?
I think they genuinely just messed up writing this question!
This is a tricky one. So, as written this is a possibility:
Insurance: Wednesday, Thursday, Saturday, Sunday
If that’s true, the argument is devastated. D eliminates that possibility, thereby protecting the argument.
For E, it doesn’t actually matter whether John works two jobs in the same day. We could have this schedule, and the argument would work:
Insurance: Monday, Tuesday, Wednesday, Thursday
Blacksmith: Monday, Tuesday, Wednesday, Thursday, Friday
The argument is still basically fine in that scenario, so E isn’t necessary. Hope that helps!
But what if instead of the situation as you described, it was
Insurance: Monday, Wednesday, Thursday, Friday
Blacksmith: Tuesday Friday
John works four days a week as an insurance agent
Fridays he works as a Blacksmith
John works five days
We could actually meet every one of the conditions without needing to work at the insurance company Monday-Friday!
Sorry for the late response! I believe you might be misreading the conditions of the stimulus. Your scenario says he worked at the insurance company on M, W, Th, F. The stimulus says that he must have worked at the insurance company Monday-Thursday that week. So no Friday.
And in the scenario you wrote, D is still true. He could not have worked Saturday or Sunday last week to fulfill the conditions. But he may or may not have worked two jobs on one day (answer E) – that is not necessary. Hope that helps.