PT80.S1.Q24 - lucinda will soon be attending

saberati

https://7sage.com/lsat_explanations/lsat-80-section-1-question-24/

For some context, I missed 5 in this section (including this one) and 4 in the other LR section which is typical for me. I BR'd my other misses and skips in this section and was able to get them all correct. This question, I haven't been able to conclusively state why all AC are either right or wrong. I think I'm messing up my diagramming... so if you see glaring errors below, please tell me where I'm screwing up!

I just guessed (A) during the test as I was out of time. In BR I diagrammed as follows:

L > NUem
NU m> WHem
_
L m> WH

which is flawed argument form
A > B m> C
_
A m>C

I skimmed over the AC for quick eliminations and I eliminated C because it contains "never" in the conclusion.

Then I began diagramming the remaining AC:

(A) My question here is do I diagram "probably" in the conclusion as "most"?
CMSMour
CMSM m> REH
_
CMSMour m> REH (probably diagrammed as most>)

I eliminated (A) because it follows a valid argument form:
Ax
A m> B
_
Ax m> B

(B) I diagrammed "generally" as most...
REH m> EG
REHour > /EG
_
REHour > EG

I eliminated (B) because while it doesn't follow the same invalid form as the stimulus

(D)
Cour > MSM > EG
_
C > MSM m> EG

I think this looks like:
Ax > B > C
_
A > B m> C
A m>C
therefore matching the question's flawed reasoning.

(E) I'm having trouble diagramming the first sentence so I reconstructed "Most cities that are regional economic hubs contain major shopping malls." to "Most cities that contain major shopping malls are regional economic hubs." Does this change the nature of the sentence?
C > MSM m> REH
Cour > MSM
_
Cour m> REH

OR am I just complicating this and its as easy as:
REHcity m> MSM
OURcity > MSM
_
OURcity m> REHcity

which follows:
A m> B
Cx > B
_
Cx m> B

E just confuses me... and I can't figure out why.

I haven't watched the explanation, nor have i looked to see what the correct answer is because I'm really trying to work this out! Thanks in advance!

EvetteCee

I drew the diagram as this:

1. residents of WH --- most --> Engineering majors
2. Lucinda ----> Engineering major

C: Lucinda --> Will live in WH

In more generic Lawgic:
A most B
C --> B
So: C --> A

And for your question about E, yes "you're complicating this and its as easy as" Lol

It should read as: cities that are REH --- most --> contain major shopping malls.

I hope that helps, let me know if you have questions.

Paul Caint

So I got this question right without diagramming. You can read for structure and common words, though I don't recommend this method if you're having trouble with Flaw Method of Reasoning questions quite yet.

Also, notice how they mix up the equivalent premises in the answer choices. In other words, the Premise 1 in the stimulus' equivalent may be Premise 2 in the answer choice.

So first I read for parallel conclusions. One of the biggest words in there is "probably." Scan all answer choice conclusions for the word probably or equivalent words, and eliminate all those that don't.

Answer choice D's conclusion is an absolute, it says something WILL happen. Not "probably will." Eliminate!

Next I started looking at premise structure. The stimuli premises are basically:

1) Lucinda will be an Engineering Major
2) Western Hall -most-> Engineering Major

In other words, our two premises are basically:

A in B
C -most-> B.

Answer choice A:
Shopping Mall will be built in our city (A in B ) - looks good so far!
Most cities are regional economic hubs -> Nope! This doesn't work. This is B -most-> C, not C -most> B!

ELIMINATE!

Answer Choice B:
Our city is an economic hub (A is B ) -> already kinda shakey here...
Cities that are economic hubs (A+B ) experience tremendous economic growth (C)?
What...this structure is just waaaay off...
A is B
A+B -> C

These premises are nowhere near our stimulus! ELIMINATE!

Answer Choice C:
Cities that are economic hubs (A) always have excellent transportation systems (B )
Our city has an inadequate transportation system (/B ) - aka, it DOES NOT HAVE B.

Does not have B?! This doesn't match our premise structure at all! ELIMINATE!

All that is left is E. Notice how answer choice E flips the premise order, but how the premises are structurally identical to the stimulus, and the conclusion is identical.

Hope this helps!

saberati

Thank you, guys.