## Can't seem to remember which PT had this justify...

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skip james

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### Can't seem to remember which PT had this justify...

...as the title said, it's a sufficient assumption. It's really bothering me... I can't remember where it's from. This problem had something to do with some skilled artists being famous (and also not famous, I think) and something about creativity. It was a pretty unique justify question, I would love it if someone could help me figure out which test it's from.

Cambridge LSAT

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### Re: Can't seem to remember which PT had this justify...

PT 39, LA, #21

Massimiliano

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### Re: Can't seem to remember which PT had this justify...

haha just took that test and got that question wrong.

Massimiliano

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Joined: Thu Jan 29, 2009 3:19 am

### Re: Can't seem to remember which PT had this justify...

actually, can anyone break this problem down?

This is how I approached it:

P1: skilled artists most creative --->abstract reasoning
P2: skilled artists some NOT famous

conclusion: abstract reasoning some famous

a little stumped after that...

TheLuckyOne

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Joined: Tue Jul 01, 2008 1:00 pm

### Re: Can't seem to remember which PT had this justify...

Ok, this question is indeed not really nice.

Diagram:

S -most-> C --> Ab
S -some-> -F

Therefore, Ab -some-> F

E: S -most-> F

Let's add this to what we already have:

S -most-> C --> Ab (contrapositive: Ab -some-> C -some-> S)
S -some-> -F (contrapositive: -F -some-> S)
S -most-> F

Ab -some-> C -some-> S -most-> F

Therefore, Ab -some-> F

If I remember correctly we cannot really deduce anything definite from a bunch of "some" statements, but theoretically it's possible from the above.

What a horrible question! LSAC you suck!

OK, here is why all the other questions are completely off:

A:
S -most-> Ab
S -some-> -F
Doesn't help us connect two elements Ab and F.

B:
Ab -some-> C -most-> S -some-> -F
Again, Ab -some-> -F is not our conclusion.

C:
S -some-> -F
We already know this.

D:
Ab --> C -some-> S -some- -F
Same as B.

I still think and will stand by my point LSAC was drunk when was writing this question unless someone points me something I'm missing here.

BTW, for the fun of it I opened Kaplan explanantions, and ... well... proved myself one more time how much they suck.

skip james

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Joined: Sat Sep 19, 2009 2:53 am

### Re: Can't seem to remember which PT had this justify...

Yeah it's a pretty unique question. It's one of my favorites, really gave me a deeper appreciation of how subtle LSAC could be.

I didn't read the LuckyOne's diagram, I'm sure it's right and all but it looked too long. Here's my own diagram of this problem, trying to be as simple as possible:

P1: SA --m---> VC

P2: VC ----> GAR

... these are combinable, you should note:

P1/2: SA --m--> GAR

so here I skip a premise because I want to point out it's function in a second when it'll be more clear.

Conclusion: GAR <----> F

so here if we prephrase out of our combined premise we have TWO possible ways to justify the conclusion:

GAP1: SA ---> F
GAP2: SA --m-->F (since a most/most gives us a some statement)

but this is where the LSAC gets subtle. They realize that there are two possible justify gaps so they rule one of them out with the premise that I glossed over.

Skipped Premise: SA <--s--> NOT F

which rules out GAP1 and leaves us with only one possible statement to justify the conclusion.

TheLuckyOne

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Joined: Tue Jul 01, 2008 1:00 pm

### Re: Can't seem to remember which PT had this justify...

Skip james, what I don't like about this question is that you can draw A --> C from A --> B and B --> C, but you cannot really draw A -some-> C from A -some-> B and B -some-> C. The two "some" groups do not necessarily overlap, so the conclusion is very shaky.

There are two ways:

1) LSAC was drunk when writing this question;
2) I'm stupid and missing something big.

Still not sure which one of the above is TCR

Regarding my previous diagram, only half of it pertains to the stimulus and the answer, the other half is to explain why other choices suck even more so ))

skip james

Posts: 262
Joined: Sat Sep 19, 2009 2:53 am

### Re: Can't seem to remember which PT had this justify...

TheLuckyOne wrote:Skip james, what I don't like about this question is that you can draw A --> C from A --> B and B --> C, but you cannot really draw A -some-> C from A -some-> B and B -some-> C. The two "some" groups do not necessarily overlap, so the conclusion is very shaky.

There are two ways:

1) LSAC was drunk when writing this question;
2) I'm stupid and missing something big.

Still not sure which one of the above is TCR

Regarding my previous diagram, only half of it pertains to the stimulus and the answer, the other half is to explain why other choices suck even more so ))

I think you're missing something. It's a justify, so with the correct AC, the conclusion follows 100%.

so look, if most skilled artists are creative, and all creative people are good at reasoning, then most skilled artists are good at reasoning. if we have 100 artists, then at least 51 of them are creative, and since ALL creative people are good at reasoning, it follows that of those 100 artists, at least 51 of them are both creative and good at reasoning.

so we have this: SA --m--> GAR

the trick here is this: you can derive a 'some' inference (i.e. the conclusion) if you have TWO most relationships from the same source. Returning to our earlier hypo of 100 artists, of which at least 51 of them good at reasoning, IF we say that most of those 100 artists, at LEAST 51 of them, are famous.

Sufficient Assumption: SA --m--> F

then what we have are 51/100 artists good at reasoning, and 51/100 artists that are famous. EVEN IF, 49 of the famous artists were NOT good at reasoning, at least 2 of them would have to be BOTH. which essentially means that SOME famous people are good at reasoning (the conclusion).

Powerscore-style, I think it looks like this: F <--m--SA --m---> GAR

... or what they call the 'most train', which is reducible to a some statement 'F<--s---> GAR'

skip james

Posts: 262
Joined: Sat Sep 19, 2009 2:53 am

### Re: Can't seem to remember which PT had this justify...

TheLuckyOne wrote:S -most-> C --> Ab (contrapositive: Ab -some-> C -some-> S)

Actually, this is where you went wrong. You shouldn't be doing contrapositives here.

S --m--> C ---> AB

reduces to:

S --m---> AB

if most birds can fly (B--m--->F) AND all flying things have wings (F--->W) then we can say that MOST birds have wings.

TheLuckyOne

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Joined: Tue Jul 01, 2008 1:00 pm

### Re: Can't seem to remember which PT had this justify...

skip james wrote:
TheLuckyOne wrote:S -most-> C --> Ab (contrapositive: Ab -some-> C -some-> S)

Actually, this is where you went wrong. You shouldn't be doing contrapositives here.

S --m--> C ---> AB

reduces to:

S --m---> AB

if most birds can fly (B--m--->F) AND all flying things have wings (F--->W) then we can say that MOST birds have wings.

S -most-> Ab
S -some-> F
F -some-> S -most-> Ab
___________
F -some-> Ab
Therefore, Ab -some-> F

See, I'm not sure we can deduce stuff from that either. Say there are 5 F, 100 S. Say 2 Fs are S, and 90 S are Ab. It's not necessary that those 2 fall into the 90, maybe, they belong to the other 10 who don't share any qualities with Ab group. The problem here is that we don't have "all" to draw any conclusions.

What am I missing again?

skip james

Posts: 262
Joined: Sat Sep 19, 2009 2:53 am

### Re: Can't seem to remember which PT had this justify...

TheLuckyOne wrote:S -some-> F

this is wrong. first off, according to the stim, it's 'S<-some->NOT F' (this should also be a hint, the correct answer choice must contain an F, since there isn't an 'F' in the stimulus; don't forget that you can't do contrapositives for some statements)

second, this is a justify. basically this question is now just this:

what ADDITIONAL premise would we need to conclude:

F<-some->GAR

from this:

TheLuckyOne wrote:S -most-> Ab

skip james

Posts: 262
Joined: Sat Sep 19, 2009 2:53 am

### Re: Can't seem to remember which PT had this justify...

TheLuckyOne wrote:
See, I'm not sure we can deduce stuff from that either. Say there are 5 F, 100 S. Say 2 Fs are S, and 90 S are Ab. It's not necessary that those 2 fall into the 90, maybe, they belong to the other 10 who don't share any qualities with Ab group. The problem here is that we don't have "all" to draw any conclusions.

What am I missing again?

STOP DEDUCING STUFF

this is a justify. just figure out what you need to ADD to your premises to get the conclusion.

TheLuckyOne

Posts: 318
Joined: Tue Jul 01, 2008 1:00 pm

### Re: Can't seem to remember which PT had this justify...

skip james wrote:
TheLuckyOne wrote:
See, I'm not sure we can deduce stuff from that either. Say there are 5 F, 100 S. Say 2 Fs are S, and 90 S are Ab. It's not necessary that those 2 fall into the 90, maybe, they belong to the other 10 who don't share any qualities with Ab group. The problem here is that we don't have "all" to draw any conclusions.

What am I missing again?

STOP DEDUCING STUFF

this is a justify. just figure out what you need to ADD to your premises to get the conclusion.

Holy... my problem was that I thoguht the answer choice was some, not most!!!

Thank you. Yeah, I def need to start studying for the LSAT ASAP because I'm loosing my shape.

skip james

Posts: 262
Joined: Sat Sep 19, 2009 2:53 am

### Re: Can't seem to remember which PT had this justify...

no problemo

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