RRS wrote:First, thank you for doing this!
I have a few LR questions:
PT 39 (Dec. 2002) Section 2, #17: necessary; I got down to the correct answer choice (B) after eliminating all the other answers with the negation test, but I always have trouble negating conditional statements. My instructor told me to put "It's not the case that" in front of them, so "It's not the case that if the Japanese drive on the left side of the road, then they are not inclined to buy cars with left-side steering wheels." Is there a way to simplify this; I can't wrap my head around what this is actually saying for some reason.
PT 61 (Oct. 2010) Section 5, #19: There's seems to be an internal BP divide about whether or not this prompt should be classified as a strengthen question (video explanation) or a sufficient question (score report). The language "justifies the above application" makes it sound like a strengthen prompt, but you also have to bridge the logical gap between the principle and the application, and that task is typical of a sufficient question. What's the best way to approach this question?
PT 61 (Oct. 2010) Section 5, #26: parallel flaw
I diagrammed as follows:
uneducated pop. => weak
(CP: X weak X = educated)
X uneducated X => commit. to pub. edu.
(CP: X commit. to pub. edu. X => uneducated)
transitive conclusion: X commit. to pub. edu.X => weak
CP: X weak X => commit. to pub edu.
The stimulus' conclusion is fallacious, because it asserts: commit. to pub. edu => X weak X.
I read this as the inverse of the transitive conclusion (i.e. both conditions are negated), so I chose answer C, which also commits the fallacy of the inverse, but BP looks at it as the converse of the contrapositive, arriving at B. Where did I go wrong?
All of these are great/tricky/interesting LR questions, and I'm glad to see you've got a pretty good grasp on each of them. I'll do what I can here to really drive the answers home.
1. I'll need to hunt this question down, as I don't have many LSATs prior to the mid-2000s. I'll start with your second question and come back to this.
2. I see what you mean about the internal divide -- it being called sufficient in one place and strengthen in another. This is actually not a contradiction though; sufficient and strengthen questions have a similar relationship to squares and rectangles.
What I mean by this is that every sufficient question you encounter will be a strengthen question, in the same way that every square is a rectangle. That's because if a premise is sufficient to guarantee the conclusion it is also strengthening it (and then some). As with squares and rectangles, its important to avoid the converse fallacy: a premise is not sufficient simply by virtue of its strengthening an argument.
I'd recommend classifying this particular problem as a full-on sufficient question. Your first tip is the "justifies" -- typically for a strictly strengthen question the prompt would read "most justifies." Also, a little birdie named Hindsight whispered to me that the correct answer choice will guarantee the conclusion, rather than just strengthen the argument.
Having read and deciphered the prompt, we can jump into the stimulus. From the first sentence we learn that if there is no currenly working qualified candidate (CQC) then Arvue should go with the most productive candidate. This reads:
no CQC >> MPC
Next the LSAT tries to trick us by writing the conclusion followed by a premise:
"Arvue should not hire Krall for the new position, because Delacruz is a candidate and is fully qualified."
Dont be fooled
the premise here is "because Delacruz is a candidate and is fully qualified," and the conclusion is "Arvue should not hire Krall for the new position."
This leaves us with two possibilities. Either (i) Krall is not a CQC, and he is not the MPC, or (ii) neither Krall nor Delacruz are CQCs, but between the two Delacruz is the MPC.
When we scope the answer choices, we see that (e) matches (ii) exactly: "None of the candidates already works for Arvue, and Delacruz is the candidate who would be most productive in the new position."Edit for grammar bad.