#19 - At a gathering at which bankers, athletes, and lawyers

[Dave Killoran]

Hi Deborah,

Yes, I'd say that in general that is true. It was never a huge part of the test in the past, and over the last decade it has appeared less frequently. When it does pop up, however, it tends to cost the typical person more time than average.

I also think that at some point in the future they'll re-emphasize it more because people have gotten used to the idea that they won't see it as much. But, I just don't know when that will happen!

Thanks!

[kappe]

I chose answer A which is wrong then I went back and chose answer B which is wrong please explain why answer choice C is correct and please direct me to which chapter I need to go back to review so I will not make the same error again .

[Nicholas Bruno]

Hi Kappe,

This is a must be true question so it might be helpful to review the Must be True information if you find you are getting alot of these problems incorrect. Also, on this question, some of the information about logical negation may be helpful.

On this question, it is easiest to diagram this out:

Banker athlete
Lawyers bankers

Since some of the athletes will be bankers, it is impossible for all of the athletes to be lawyers. Since the logical opposite of all is some, at least some of the athletes will not be lawyers. Thus, Answer Choice C is correct.

I hope that helps!

[Khodi7531]

I think of myself to be pretty well versed on the LSAT and on LR. But 19 is just retarded.

Yes we get B > A and L > notB

We can diagram it as B > A and notL ....then you can get a some statement from A and L. And I get now that it's saying you can deduct that if All B's are A's... that you can definitively conclude that at least ONE A, can not be L. No matter what.


But is this way of thinking like a new thing? Why is it that i've NEVER seen a question demand such an answer in this way. I chose B and I was between B and C because they same the same exact thing. Some statements can be read in both ways can they not?

I mean when you read it from top to bottom with B as the sufficient, it's notL some A.I don't get the issue and I don't understand where this came from. Because now I feel like this can just confuse someone for conditional chaining that they've learned for future questions.

[Daniel Stern]

Answer choices B and C absolutely do not say the same exact thing, and recognizing the difference is important.

C, our credited response, draws a conclusion about athletes: as you correctly point out, there's going to be at least one banker-athlete at the party, and he can't be a lawyer, so C is true: there is going to be an athlete who is not a lawyer at the party.

However, B draws a conclusion about the lawyers at the party that is not supported by the stimulus info. Every single lawyer at the party might also be an athlete. In fact, it could be an entire party of athletes, some of whom became lawyers and some of whom became bankers. We just don't have any information in the stimulus about whether the lawyers are athletes or not.

I hope that helps you to understand. Although this may be tortured logic that is rarely seen in this particular form on the test, the underlying concepts -- that is, diagramming the absolute sufficient/necessary relationships and realizing what can and cannot be validly concluded from them -- are nearly ubiquitous on the test, and you should study study study them!

Best,
Dan

[Khodi7531]

Ok i'm still not understand. So explain to me in this way...

The diagram is B > A and notL

The rule to read this conditional logic is that A and notL are a "SOME" statement, correct?


So is the some statement read in only; A SOME notL .... can it be notL SOME A (which is basically B, since we can reverse the some statements can we not?)

Can we negate the A and the L to conclude; L SOME notA ?


Just trying to see this by rule since I can't understand conceptually what you mean - over the internet at least.

[Emily Haney-Caron]

Hi Khodi,

I'm having a hard time parsing your question. Could you try rewriting it with more detail? That will help us give you the best possible answer.

Thanks!

[Khodi7531]

I'm asking how you make an inference from the conditional logic we drew up from this question.


It says B > A AND notL

You can create a "some" inference from A and notL. Don't B and C both say this? Because "some" statements can be reversed.... (example: A some B .... also, B some A). Can't you do this with notL some A... or can you do L some notA (because you're negating it)


The way to answer this question is obviously somewhere in the "some" logic that I have messed up. I know you can read some statements in reverse but can you negate them? Can you not? What ways can and can't I read the inference that's made from this statement: B > A AND notL ?

[Alex Bodaken]

Khodi7531,

Thanks for the question. Let me see if I can help a bit to explain why answer choice (C) is credited.

We know that there are some athletes (A), bankers (B), and lawyers (L) present. And we know that all of the bankers are athletes. We can think of this as this as a new subgroup - let's call them BA (they are both bankers and athletes).

We know that ALL of these BA folks will not be Ls because none of the lawyers can be bankers (and vice-versa). So we therefore know that there must be some population of athletes (whichever are BAs) that are not Ls. This is what answer choice (C) says, making it correct.

Hope that helps!
Alex

[Khodi7531]

Hey Alex, thanks for that. I understand the logic of that...because it's essentially saying B is A...and if B isn't something then A can't be it either.

However, i'm trying to break this down into more of a fundamental lesson. Just going by diagramming...a some statement can be reversed, right? If some A is B, you can conclude some B is A. Now, if B is A, and B is not L... you can conclude A and not L....BUT CAN YOU CONCLUDE... the reversal of not L and A? (as in not A.... some L)

I'm trying to see what you can reverse what you cant. I don't like thinking of this conceptually so I always try to make it mechanical.

If there are two things necessary for one sufficient acronym - like B - then you can make a 'some' statement from them. I'm trying to see how is the correct way to read that. Because I was reading it in many different ways so I need to see what the correct way to read it is.

Does that make sense?