Q23 - Three million dollars was recently stolen

[ohthatpatrick]

Question Type:
Match the Flaw

Stimulus Breakdown:
Conclusion: Some of the mayor's staff are suspects.
Evidence: All of the suspects are former employees of the CTO. Some of the mayor's staff are former employees of the CTO.

Answer Anticipation:
This author is trying to make a "forced overlap" inference. She is trying to combine an "All" and a "Some" statement. The problem is that the "All" statement is about "All suspects .." and the "Some" statement is NOT about suspects. Thus, there is no legal inference to be made.

We should consider converting the botched attempt into abstract ideas like A, B, C, so that it's easier to match up / eliminate answer choices. The author is saying

All A's (suspects) are B (former employees).
Some B's (former employees) are C's (on the mayor's staff).
Thus, Some A's are C's (some suspects are on the mayor's staff)

Correct Answer:
B

Answer Choice Analysis:
(A) This pair of premises lacks an All statement, so defer and move on.

(B) This looks good.
All S's are B's.
Some B's are C's.
Thus, some S's are C's.

(C) This pair of premises gives us TWO All statements, so defer and move on.

(D) This conclusion is "All", not "Some", so defer and move on.

(E) This conclusion is "All", not "Some", so defer and move on.

Takeaway/Pattern: Since (B) was the only answer with the right quantity ingredients (an All premise and a Some premise that were combined into a Some conclusion), we can quickly filter out the others and confirm that (B) is making the same error.

#officialexplanation

[kdaddymax]

I got this question right, but I spent a lot of time doing so. I find myself having trouble with these types of questions, especially when they are near the end of a section and I'm low on time. What's the best way to approach these parallel reasoning questions that center around specification terms like "some," "most," and "all?"

Is it best to try to diagram the stimulus example quickly or look for similar term use structuring (for example, choice A would be "some" --> "some" --> "some", choice B would be "some" --> "all" --> "some")?

[ohthatpatrick]

When it comes to the topic of

"running low on time ... hit a Parallel reasoning question toward the end of the section", the general advice would be skip it and come back to it.

Unless you're much more accurate on these than you are on other questions towards the end of an LR section, then you should save these time-suckers for last.

When we attempt them, we often need to live with cutting corners:
- be more willing to pick the first answer you're very warm to, without exhaustively disproving the other four

- spend long enough on the stimulus that you get a clear picture of what you're looking for, so that you can make quicker, more decisive mismatch eliminations.

When it comes to "Quantity Inferences" .. i.e., trying to prove that "there's at least SOME overlap", keep it simple.

The two legal ways to make quantity inferences are

Most A are B
Most A are C
------------------
Some B and C

(key feature: both Most claims must be about the SAME group)

All A are B
+
Some other fact about A and C
-------------------------------------------
resulting inference would depend on the 2nd fact, but it's usually still just "Some B are C"

(key feature: you need a 2nd idea that's about the TRIGGER of the "All" statement. Getting a 2nd idea about B would be useless, unless it was an "All B's are _____" statement)

[JesseL294]

So I have a question about some statements that tripped me up on my timed run through this question.

Is it logically possible to read the last statement "the mayor's staff includes former employees of that office" as "some MS are FE" as well as "some FE are MS"? Or is this not sound? If not, why not?

Thanks in advance!