Q20 - Ann will either take a leave

[c.s.sun5]

Can someone please explain to me how you go about solving this problem? How would the graph look like (is there a need for one)?

Thanks a bunch~~

[aileenann]

Sure thing. I don't know that we need a graph, but I do think some conditional logic would help spell this out in more detail. I would do it as below

l.o.a. or quit
l.o.a. or quit -> t.f.
doesn't know about t.f. -> allow l.o.a.

therefore, quit -> knows about t.f.

Since the argument is asking us for an assumption, we can fill in whatever missing logical link from this argument with such an assumption. Do you see anything missing?

One thing that strikes me is we know the conditions for Technocomp allowing Ann to take a l.o.a., but I am not sure we know whether Ann will *only* quit if the company finds out about her fellowship. Isn't it possible she might quit even if she is permitted to take a l.o.a.? Do you see that in the answer choices?

[andyevans000]

The initial diagramming really helped. From that, this is how I worked it out. I think the logic is sound, so please someone correct me if I'm wrong.

Since, our final premise is:
NOT know TF --> Allow LOA
and our conclusion is:
Quit --> know TF

We must take the contrapositive of the conclusion above to allow for the linkage:
NOT know TF --> NOT Quit

So the sufficient assumption must be:
Allow LOA --> NOT Quit

Since the above isn't in any of the answer choices, we must look for additional inferences. As we know from above, Ann either quits or takes the LOA, therefore Not Quit = Take LOA, and in turn, Allow LOA --> Take LOA is another sufficient assumption, which word for word answer D.

[shaynfernandez]

This question has me all turned around. I choose D because all the other answers have absolutely nothing to do with the argument. Yet i still can't see the gap I am being asked to fill. How I break the argument up is like this:
1. Ann will do one of two things if she is offered the teaching fellowship: take a leave of absence or quit. (also that's the only reason she would do one of these two things... It's necessary)
2. The only way she can have a leave of a absense is if technocorp doesn't find out about the offer.
3. The author concludes that the only way she will quit is if they find out.

1. Quit or leave of absense --> offered teaching fellowship
CONTRA: ~offered TF --> ~(Quit and leave of absense)

2. LoA --> ~find out
CONTRA: find out--> ~LoA --> Quit

3. Quit --> Find out
CONTRA: ~Find out--> ~Quit --> LoA

I don't see how this gives us any gap. I understand that in 1. the option of quitting is still there even if they don't find out. But it seems like this argument is just explaining the routes Ann has and doesn't really need an assumption to justify it...

What am I missing?

[ManhattanPrepLSAT1]

Here's how I see the statements.

Q ---> ~LA
~Q ---> LA
Q or LA ---> OF
~FO ---> ALA
FO ---> ~ALA
----------------
Q ---> FO

Notation Key: Q - quit her job, LA - take a leave of absence, OF - offered a fellowship, FO - Technocomp finds out she was offered fellowship, ALA - allow a leave of absence

The first two stem from the fact that she will quit her job or else take a leave of absence. The third statement comes from the fact that she would not do either unless she were offered a fellowship. The last two stem from the fact that if they don't find out, they'll allow a leave of absence, but not otherwise.

For this sufficient assumption question, we'll simply snag the two relevant premises (which we can identify because of the matching terms in the conclusion).

Q ---> ~LA

~ALA ---> FO (contrapositive of 4th statement above)
---------------
Q ---> FO

The gap being ~LA ---> ~ALA or in the contrapositive form
ALA ---> LA, perfectly expressed in answer choice (D).

Does that clear things up?

[ManhattanPrepLSAT1]

For a very similar example to this one check out PT9, S2, Q23 - A poor farmer was fond

The argument structure is nearly identical.

[shaynfernandez]

Matt,
So the relationships in the premises are bi-conditional (one or the other but not both)?

[ManhattanPrepLSAT1]

They're not bi-conditionals. That would imply that the two terms are mutually dependent. Instead it is that you are given information about what happens if she takes a leave of absence, but also what happens if she doesn't take a leave of absence.

LA ---> ~Q
~LA ---> Q

Anytime you stack up two conditionals that are the negation of each other, and state that both are true, you are implying that exactly one of the two events will occur. The first statement above guarantees that she will not do both, and the second statement guarantees that she will do at least one of the two terms. The combination guarantees that she will do exactly one of the two terms (quit her job or else take a leave of absence).

[timmydoeslsat]

They're not bi-conditionals.
LA ---> ~Q
~LA ---> Q

I would say those are biconditionals. Although the positive/negatives of each variable imply the presence and absence of exactly one variable, it is the case that both variables in their form are sufficient and necessary for the other.

LA <---> ~Q

[patrice.antoine]

They're not bi-conditionals. That would imply that the two terms are mutually dependent. Instead it is that you are given information about what happens if she takes a leave of absence, but also what happens if she doesn't take a leave of absence.

LA ---> ~Q
~LA ---> Q

Anytime you stack up two conditionals that are the negation of each other, and state that both are true, you are implying that exactly one of the two events will occur. The first statement above guarantees that she will not do both, and the second statement guarantees that she will do at least one of the two terms. The combination guarantees that she will do exactly one of the two terms (quit her job or else take a leave of absence).

Which begs of me to ask:

is "A or else B" the same as "A or B" (where in the latter, both can occur) ?

[patrice.antoine]

Also is not A or else B to mean:

If not A --> B

If not B --> A

..so in reality, if ~LA --> Q and ~Q --> LA ??

I got this question right without using any conditionals, lol, but an explanation of "A or else B" means LA ---> ~Q and ~LA ---> Q would be greatly appreciated!

[wj097]

Also is not A or else B to mean:

If not A --> B

If not B --> A

..so in reality, if ~LA --> Q and ~Q --> LA ??

I got this question right without using any conditionals, lol, but an explanation of "A or else B" means LA ---> ~Q and ~LA ---> Q would be greatly appreciated!

I believe your interpretation of A or else B is correct (Either A or else B => A, B, A&B), but the statement here is unique.

Here, A&B means "quit as well as loa/return"..there's conceptual contradiction; you cannot do both at the same time at least in our conceptual world. I think that is why Matt was able to put it as a biconditional. Normally you wont.

Thx

[zip]

I found this problem easier to solve without diagramming. But I would say that the diagram is an either or but not both for the conditions. That is a bi conditional. Further, this leads to the inference, not tested, that the fellowship was offered. La <--> ~Q --> La or Q ( the unless class La or Q --> Of) --> Of

With respect to the question which premise enables the conclusion Q -->Fo to be validly drawn, choice D, ALA --> La implies ALA--> La-->~Q , so if Q not ALA, not ALA, Fo. Q--> ~ALA (since A's absence requires Fo)--> Fo. So the contrapositive of the credited choice implies the conclusion.

I think that question Pt 9, S2, Q23, is easier because the answer directly contradicts the possibility that there are honest farmers who are rich. But this one too, can be parsed by plugging in the full implications, which are bi-conditional, and thus give us tons of implications based on a conditional premise.

[zip]

Sure thing. I don't know that we need a graph, but I do think some conditional logic would help spell this out in more detail. I would do it as below

l.o.a. or quit
l.o.a. or quit -> t.f.
doesn't know about t.f. -> allow l.o.a.

therefore, quit -> knows about t.f.

Since the argument is asking us for an assumption, we can fill in whatever missing logical link from this argument with such an assumption. Do you see anything missing?

One thing that strikes me is we know the conditions for Technocomp allowing Ann to take a l.o.a., but I am not sure we know whether Ann will *only* quit if the company finds out about her fellowship. Isn't it possible she might quit even if she is permitted to take a l.o.a.? Do you see that in the answer choices?

This was much more the approach I took. If I will take it, then they only way I don't ( quit) is if it's not offered, and that only happens if I they find out .It actually is far more intuitive, for me at least , to use words rather than symbols. It also prevents the all to easy missymbolism which affects many of us on these rather convoluted logical arguments where time is so pressed.

[LSATeater]

I actually really liked this question because it demonstrates that formal logic questions should be gimmes on the LSAT. In other words, there are NO truly difficult formal logic questions on the LSAT logical reasoning sections only formal logic questions which we think are difficult. Once you untangle all the wordy language and premises, the deduction which you are asked to make is surprisingly simple.

Here we are told that Ann will either leave (L) or quit (Q). Then we are told that her company will allow her to leave (aL) if it has no knowledge of her being offered a fellowship (~K) but not otherwise. So really, this is an if and only if statement:

~K-->aL and K-->~aL, or, even more simply, ~K<-->aL.

The conclusion is that if she quits (Q) then her company has knowledge of her offer (K): Q-->K.

What's the sufficient assumption?

Well we know that she will either quit or leave (no third option) and that K-->~aL. So, if her company has knowledge, then she must quit since she cannot leave:
K-->~aL-->Q.

And what if her company does not have knowledge (~K)? In that she case she is ALLOWED to leave but that does not mean she has to leave. In formal logic:
~K-->aL--> L or Q. Since we are to conclude that her company has knowledge of the fellowship offer if she quits then we must cross out the "or Q" part because then the conclusion is contradicted. So, we must assume that:
~K-->aL-->L.

And that is the answer, not hidden beneath a contrapositive or additional inferences, as choice D has it.

[natalie.seni]

I found this question really difficult!

I'm a bit confused as to whether or not the second sentence is a biconditional since the poster above me mentioned that it was, but Matt Sherman, in an earlier post, said that it isn't...I'm confused by the "but not otherwise" part of the sentence. Can someone clarify the proper way to diagram and solve this problem?

[ohthatpatrick]

I would say that we ARE dealing with at least one bi-conditional in this argument.

The first sentence you could split hairs about whether to call it a bi-conditional, but the second sentence is definitely bi-conditional.

Example:
If Marcy comes to the party, it will rock, but not otherwise.

That guarantees us both
Marcy comes -> party rocks
Marcy doesn't come -> party doesn't rock

Any time you have
A -> B
and
~A -> ~B

then you have a bi-conditional. Either they both happen or they both don't.

So, here, either Technocomp finds out about the fellowship and DENIES her the leave of absence, or Technocomp DOESN'T find out about the fellowship and therefore GRANTS her the leave of absence.

The first sentence is more of a judgment call. It's technically one huge conditional idea.

~Offered Fellowship -> Won't Quit and Won't LOA

Quit or LOA -> Offered Fellowship

If you were trying to avoid conditional logic here, I would suggest taking your time with the first sentence and putting yourself in Ann's shoes.

She wants this fellowship. She's kinda sick of her job but it's a job. She's not the type to just quit a job without something else lined up.

If she's not offered the fellowship, she's staying put at Technocomp.

If she IS offered the fellowship, who knows? She might quit. She might just take a yearlong leave of absence. Or she might just turn down the fellowship.

Getting the leave of absence hinges entirely on keeping the fellowship a secret from her bosses at Technocomp.

Finally, the conclusion makes an incredibly extreme claim "the ONLY way Ann will quit her job is if Technocomp finds out she's been offered the fellowship."

To figure out what's missing, let's figure out how we're still allowed to argue the Anti-Conclusion:
Ann quits her job, even though Technocomp DIDN'T find out about the fellowship.

Well, could we just say maybe Ann gets sick of her stupid coworkers and THAT'S why she quits?

No ... we had a rule early on that told us Ann does NOT like to quit. If she isn't offered the fellowship, she will stay put. She will not quit.

So we could fairly say that the only way Ann will quit her job is if she's first offered the fellowship.

Well, when she's offered the fellowship, she has a few options: quit, take a leave of absence, or turn down the fellowship.

The conclusion seems to think that Ann would only quit if Technocomp found out about the fellowship. Why? Why does it matter whether or not Technocomp finds out?

Oh yeah, because that's what determines whether or not Ann gets offered a leave of absence.

So the author must be assuming that Ann's BEST CASE SCENARIO is getting the fellowship and taking the leave of absence, and Ann would only quit if that option got taken off the table.

That's what (D) is saying.

[yeh.briann]

I understand andyevans000's explanation quite well, and I can see why D is the right answer because of his explanation. However, I am confused as to why, instead of taking the contrapositive of the conclusion, we could not have also taken the contrapositive of the premise that "Technocomp will allow her to take a leave of absence if it does not find out that she has been offered the fellowship, but not otherwise."

So I have as the last premise:
NOT find out --> Allow LOA
and our conclusion is:
Quit --> find out

Why can't we take the contrapositive of the last premise and get: NOT allow LOA -> find out? Since the conclusion is Quit --> find out, I had been trying to connect "NOT allow" to "Quit Job" (NOT allow --> Quit). Why doesn't this work?

[zen]

Hey everyone. This is a tough question but utilizing your process of elimination skills will make it considerably easier.

Most of the Answer Choices can be eliminated without even worrying about the conditional logic.

Check it out:

(A)- Inform on her?? We have no info about how they could find out! Not to mention this is irrelevant to the conclusion.

(B)- The reason? WDGAF about her reasons!

(C)- This tempted me for a sec but then I reread and realized, "how do we know this prestigious university is a competitor of Technocomp?? We don't. Technocomp doesn't even sound like a university from a common sense standpoint but either way, we don't know these two institutions are in competition.

(E)- This does not seem to be the case from the info we have in the conclusion! It says when she's offered the fellowship she will have a decision-- whether to take a leave of absence( provided technocomp dosen't find out she got the fellowship) or she can quit! This choice happens after(in a temporal sense) she is offered the fellowship and deals with how she is going to balance her duties to her current employer with the new responsibilities regarding the fellowship! She obviously can't do both at the same time, so she's gonna have to find a way to abstain from her current duties.

Correct Answer:

(D) So if she's offered the fellowship, she can do one of two things in order to do the fellowship: She can take a leave of absence or she can quit. If she'll only quit if Technocomp finds out, we can infer that if she gets the fellowship and they don't find out, she'd just take a leave of absence!

Hope this helps!

[aaronwfrank]

After looking at this again (I originally guessed B), I noticed it's possible to use the key premise method advocated by many instructors.

This isn't a foolproof technique, but in this case "leave of absence" and "allowing a leave of absence" are both missing from the conclusion. The right answer should include one or both of these terms.

We're then left with just (C) and (D). And as many have mentioned, we have no idea whether this university is a Technocomp competitor, which makes it out of scope, and we can rule out (C), leaving (D) as the correct answer.