Blueprint LSAT Prep's ongoing ask-an-instructor extravaganza Forum

[Captain Rodeo]

You don't, which is why I try to point it out when I see someone going down that path. The adrenaline on test day should keep you moving, but if you get used to going off on logical tangents, bad things can happen.

+1

Thanks

[bp shinners]

D-d-d-danger zone! Let's go.

[lsatkid007]

Hey BP
I know when I have a "if and only if" statement it's diagrammed as <----> which translates to both. So if Jay is going Beth is going, does that mean if one is not going the other is also not going?

Second, No A's are B's is diagrammed as A <--l--> B which can also be A --> ~B and is translated to not both. In games if we have a not both do we mark it in the out column. For example if A are in then B is out. Does that mean one of those will be out.

Third, does this mean anything other than "If A is not going then B" is going ~A --> B. It's not a both rule or anything like that?

Finally, do "some" and "most" statements don't have any CP?

Thanks BP

[tuffyjohnson]

only = necessary
the only = sufficient
if and only if = <--->

But what about:

only if = ?

[bp shinners]

only = necessary
the only = sufficient
if and only if = <--->

But what about:

only if = ?

"Only if"=necessary. Tricky because of the "if", but "only" wins out.

[bp shinners]

Hey BP
I know when I have a "if and only if" statement it's diagrammed as <----> which translates to both. So if Jay is going Beth is going, does that mean if one is not going the other is also not going?

A few problems here. First, what you wrote about Jay and Beth doesn't create the love/Must be Together relationship. You have a tag-along relationship, so if Jay goes, Beth does; if Beth doesn't go, Jay doesn't go; but that's it.

If, instead, the rule read: Jay goes if and only if Beth goes (or if there are two rules that read: If Jay goes, Beth goes; if Beth goes, Jay goes), then you'd have the Must be Together relationship.

So let's assume we have the rule as written above. This creates two worlds: Either both go, or neither goes. If either skips it (i.e. doesn't go), then the other one doesn't either because they Must be Together. Without one, you can't have the other. And if you have one, you know the other is there, too.

It's very easy to start viewing tag-along rules (If A then B) in a similar manner; don't make that mistake.

Second, No A's are B's is diagrammed as A <--l--> B which can also be A --> ~B and is translated to not both. In games if we have a not both do we mark it in the out column. For example if A are in then B is out. Does that mean one of those will be out.

That means AT LEAST ONE of them will be out (in an In and Out game - in a multigroup game, it just means I won't have both together, i.e. can't be both). So you can make an option in the out group for A/B.

However, it's important to note that BOTH CAN BE OUT. This rule just means "Not Both", which would be satisfied by neither being in.

Third, does this mean anything other than "If A is not going then B" is going ~A --> B. It's not a both rule or anything like that?

Yep - it means A or B. In other words, at least one has to be IN. Because as soon as you put one out, the other's in (since the contrapositive is Not A->B). You can make an option in the IN group for this rule. It's rare that this will show up in a multigroup grouping game; it's significantly more common in an IN and OUT grouping game (if you can explain why, you've reached LSAT ninja-dom).

Finally, do "some" and "most" statements don't have any CP?

Correct. Quick rundown:
All/None - no inverse, no converse, yes contrapositive
Most - no inverse, no converse, no contrapositive
Some - no inverse, yes converse, no contrapositive

An an example for 'Most', think about this:
Most people who speak English don't live in England.

That's a true statement - there are billions of people outside of England who are English-speakers. Take the contrapositive, though, and you'd get:
Most people who live in England don't speak English.

Not even close to true.

[wtrc]

Hey BP,

In our study group last night we went over this one, but I was wondering if you could provide more clarity. PT 64, S3, #21.

C, D, and E are obvious eliminations. But I was stuck between A and B, and ultimately chose the wrong answer. I got some explanation last night that was helpful, but wanted your take.

Thank you!

EDIT: If you have a chance, also PT64, S1, #16.

Your explanations are always so great. Thank you!

[Fianna13]

Hey BP,

can you go over questions PT 60, s1, # 15 and PT 61, s2, #16? I feel they are similar arguments, but the right answers do not share same characteristics.

[Dr. Dre]

Unrelated to LSAT:


why doesn't BP have a Wikipedia page?

[tuffyjohnson]

BP, if my goal is to be able to do tiered, linear, level 4 games in in 10 minutes should I do every available game like that first or do repeats of the same one until I get there?

[bp shinners]

Sorry for not updating before this - I'm in DC today for a law fair, so I'll get to these either later tonight or tomorrow at some point (I don't have easy access to PTs on my iPad).

[bp shinners]

BP, if my goal is to be able to do tiered, linear, level 4 games in in 10 minutes should I do every available game like that first or do repeats of the same one until I get there?

If you want to get faster, I would recommend going back over games and seeing where you took too many steps to get to the right answer. If you're going over 10 minutes on a game, then you're either spending a ton of time staring at the page thinking, or you're doing too much work (if you just sat there and wrote out every possibility, it would probably take you less than 10 minutes for most games, so there must be wasted effort in there somewhere).

So look back over the games you've done, see where those inefficiencies are, and eliminate them next time you go through the game. Do that until you feel you learned your lesson (I feel like Mrs. Krabapple telling Bart to write something stupid on the board during the opening credits), and you should be able to carry that meta-deduction to other games, thus reducing your time!

Honestly, the deductions always come from the same rules/rules combinations. Once you start to notice that pattern, you can fly through the games relatively quickly, confidently, and accurately.

[alacrity]

PT 60 section 3 #24

This question is one of the few that still troubles me after review. I understand why A,D, and E are incorrect, but I'm having trouble articulating why B is correct and C isn't.

I'd appreciate it if you could help me with this question bp.

[Captain Rodeo]

Hey BP! Hope you're having a blast in D.C.

So, my Q is for PT31-S3-Q26

I was between (C) and (B). Chose (C); the credited AC is (B).

My issue with this problem is that it contains an intermediate conclusion. That's not the problem exactly- but there is an assumption from the first premise to the IC, then from the IC to the Main Conclusion.

(B) seems to link the assumption between the P1 and IC to the Main Conc

(C) seems to link the assumption between the IC and the Main Conc

I saw the first assumption as (between P1 and IC): Assumes that nonthreatening dialogue will cause employees to generate their own ideas

The second assumption as (between IC and Main Conc): Nonthreatening dialogue with emphasis of positive contributions will help employers implement their ideas


A Necessary Assumption Q would only ask us to find one of these assumptions- I feel like I may be missing something- and that leads to my question: Am I supposed to carry the First Assumption over into the IC?

In other words, the Second Assumption would be a little different: Nonthreatening dialogue, containing employee generated ideas, with emphasis of positive contributions will help employers implement their ideas

If so, (B) totally makes sense. I was just confused because it seemed (B) worked for one part of the argument, and (C) worked for another.

What am I missing here? How do questions with more than one assumption function differently in Principle-Support (or, I guess even Principle-Identify) questions versus Necessary Assumption Qs?


Thanks!!!

[Captain Rodeo]

Unrelated to LSAT:


why doesn't BP have a Wikipedia page?

+1

[bp shinners]

First, sorry for the delay in response - I've been up and down the East Coast the past few days for marketing events. If I met any of you, nice to meet you!

In our study group last night we went over this one, but I was wondering if you could provide more clarity. PT 64, S3, #21.

C, D, and E are obvious eliminations. But I was stuck between A and B, and ultimately chose the wrong answer. I got some explanation last night that was helpful, but wanted your take.

So this is all about the way the argument is laid out:
Bunch of background BS I don't care about
Checkers refused the coupons
Accepting the coupons would have cost Checkers nothing
Accepting the coupons would have satisfied some of their customers
________________________________________________________
Checkers was motivated by a desire to stick it to Marty's Pizza

Big jump here - I never connect either of my premises (it would have cost them nothing while satisfying customers) to my conclusion (they must have been motivated by spite). I need an AC that does this.

A gives me exactly what I'm looking for. To paraphrase, "Any company that won't take coupons from a competitor when it would make some of their customers happy must be motivated by spite."
Here, Checkers didn't take a competitor's coupons when it would have made some of their customers happy. That's sufficient, according to AC A, to let me know they were motivated "solely by a desire to hurt that competitor", which is my conclusion. If I accept A, then I must also accept that Checkers was motivated by spite.

Let's look at B: "If I want to stick it to my competitor by not accepting their coupons, then I won't do it even if it would help my customers and cost nothing." Well, I've reversed my sufficient and necessary there. I don't know if Checkers wanted to stick it to Marty's - that's what I'm trying to prove. This answer choice doesn't give me a general rule that tells me something sufficient for me to come to the conclusion that Checkers was just sticking it to Marty's.

In a sufficient assumption question (or in any type of conditional logic), you can view the If/Then statement as a rule that allows you to come to a conclusion. That conclusion is the necessary condition.

For instance, "All hockey fans like a fight. I am a hockey fan. Therefore, I like a fight." I can come to that conclusion. However, I have absolutely no way of coming to the conclusion that someone is a hockey fan ;if they like a fight, they might just be a boxing fan. Or a jerk.

So when you have a sufficient assumption question, you need the new term/idea that shows up in the conclusion to show up in the necessary condition of the answer choice. In A, my conclusion shows up as the necessary condition; in B, it shows up as the sufficient. A can be correct (assuming the sufficient condition matches the premise/premises); B cannot be (since there's no way for me to get my conclusion as a necessary condition).

And, just as a note, this is a common way for them to trick you - throw the correct terms in the AC, but put the necessary condition in the sufficient condition.

As a general rule, if a new term/idea shows up in the conclusion of a sufficient assumption question, I'm looking for an answer that says, "If (premise of stimulus), then (conclusion of stimulus)." That's VASTLY simplified, but if you can understand generally why that's what you're looking for, you should be in good shape.

EDIT: If you have a chance, also PT64, S1, #16.

A bit of a tricky one here. The argument:
Democracy in not possible in the absence of consent.
The view that everyone is out for themselves implies that this consent is impossible.
_______________________________________________________________________
Therefore, social theorists who believe the third statement above also believe democracy (like resistance) is futile.

Big tell in this one - a lot of "believe"s in the conclusion. "Belief" is an important word on the LSAT because it doesn't mean that something is true; just that it's believed to be true. And people can believe all sorts of crazy stuff. So while the argument tries to show that anyone who believes that third statement is logically committed to the view that democracy is futile, it doesn't mean that they will actually believe it. I can believe any type of crazy, illogical stuff I want; and so can these social theorists.

So just because I believe that all cats are awful pets doesn't preclude me from believing that my friends cat, Peanut, is pretty bad-ass and a good pet. It is not logical, but it is often true.

[bp shinners]

Hey BP,

can you go over questions PT 60, s1, # 15 and PT 61, s2, #16? I feel they are similar arguments, but the right answers do not share same characteristics.

PT 60 S1 #15
So we have a flaw (in Rebecca's argument) question.
Camille says that manufacturers exaggerate the monetary savings of their customers (shocker!) because blah blah blah.

Rebecca responds:
My water bills have gone down since I switched to these products.
__________________________________________________________
Therefore, the manufacturer's claims aren't exaggerated.

Well, the premise here doesn't really prove the conclusion (shocker in a flaw question). Her bills could have gone down while savings were still exaggerated. Maybe she's saving $10/mo, but the manufacturers claimed she'd get up to $1000/mo in savings! Just because her water bill is low doesn't mean it's as low as it was claimed. And that's B.

PT61 S2 #16
Similar, but a little different (a bit because of the logic, a bit because of the question type).
Argument:
Magic machines change heat into electricity.
Steel manufacturing generates a lot of heat.
_______________________________________
Therefore, if steel manufacturers used magic machines, they could save money.

So I know I can use these magic machines to generate electricity. Which is, you know, expensive for a large business. However, these magic machines don't just show up out of nowhere and give you electricity - there are other costs involved. In order to get to my conclusion that I'm saving money, I need to know that the electricity I can generate will offset those other costs, and that's C.


So the two are somewhat related - they both are talking about costs of installation. However, the water-saving faucet question is more about relative logical force - low doesn't equal lower. The magic machine was is more about exclusivity/incomplete comparison - saving money in one area doesn't mean saving money overall.

In short, the topic is more similar than the logic ends up being.

[bp shinners]

PT 60 section 3 #24

This question is one of the few that still troubles me after review. I understand why A,D, and E are incorrect, but I'm having trouble articulating why B is correct and C isn't.

I'd appreciate it if you could help me with this question bp.

Alright, I've got a strengthen principle question here. When I'm dealing with a question of this type, I'm literally just looking for an answer choice that says, "If I have my premises, then I have my conclusion."

So what are my premises and conclusion?
If your record sells well, you might be too trendy to be underground (or too hip to be square).
If your record doesn't sell well, you might just suck.
__________________________________________________________________________________
Record sales aren't a reliable indicator for underground group success.

In order for my premises to prove my conclusion (in other words, in order for the music critic's argument to be justified), I need to know that sucking or being too trendy means that you aren't a good indie rock group. That would allow me to get to my conclusion that record sales don't tell me about that success. And that's B.

C, on the other hand, only deals with half of the music critic's argument - the good sales/trendy part. Since I'm looking for something that justifies his argument, I need it to incorporate all aspects of his argument. Additionally, ignoring the part of his argument about weak sales doesn't let me get to the conclusion about sales being irrelevant, because C only deals with records that sell well.

[bp shinners]

Unrelated to LSAT:


why doesn't BP have a Wikipedia page?

+1

A very good question...

[bp shinners]

(C) seems to link the assumption between the IC and the Main Conc

There's where you're going wrong. C doesn't link that assumption. The whole thrust of the sociologist's argument is that these employees should be made to feel a part of the process. (C) removes them from that process (by stating that the ideas come from a dialogue in which they have not participated). So (C) doesn't really help the sociologist's argument along, and it can't be the answer here.

Yes, I know the stimulus does say that these dialogues are happening after the decision has been made, and we're just trying to fool the employee. However, it DOESN'T say that doing it this way (as opposed to just bringing the employee in and actually letting them contribute to the idea) makes it more likely for the ideas to be implemented. The whole point is that the employee has to believe they contributed, and that can happen whether they actually participate in the idea-generating dialogue or not, so (C) - which focuses on them NOT being involved in that dialogue - doesn't help this argument.

(B), on the other hand, connects everything together. If employees are more likely to carry out ideas that they think they helped generate, then employers should try to make them feel that way.

What am I missing here? How do questions with more than one assumption function differently in Principle-Support (or, I guess even Principle-Identify) questions versus Necessary Assumption Qs?

They don't. Arguments with more than one assumption can have either assumption show up in the answer choice (or both, depending on the question and question type). However, as stated above, (C) is a little off here, so it's not the right answer.

[lsatkid007]

Hey bp
Lately I've been getting my ass handed to me by the RC passages. So I decided to take your advice and tackle each paragraph like a LR stim and go real slowly. It's worked, my score went up and I have a better understand of the passage but it's taking me waaaaaaay to long. How long should I keep going slow?

Thanks for the help

[Captain Rodeo]

Thanks so much for clearing that up.

I have another question for when you have time (short!): is "except when" the same, logically as "except"? (Negate the Suff keep the Necc)

[alacrity]

Thank you bp!

[TTX]

Hi.
I have posted this question on the main forum but no one has touched it yet. It would be really helpful if you could answer my question or point me to the right direction.

PT 3 LR 1 Q 4

I understand it as a must be true question with a conditional in the stimulus.
The stimulus essentially says If an architecture is to be both inviting [A] and functional , then it must be unobtrusive [~C].
Simplified: If [A] + [B} --> [~C].

Then it goes on to to say that modern architects have "violated this precept" by producing buildings that are no longer functional (so ~B). I'm having a difficult time interpreting the phrase, "violated this precept." How should one translate this phrase back into the original conditional statement?

More generally, since a precept is just a principle, and let's say I have a principle that is a conditional statement (If A then B), when someone says that the principle has been violated, does that automatically mean the negation of the necessary condition, or is it more like: even if A, still not necessarily B.

Thanks for the help!

[bp shinners]

Hey bp
Lately I've been getting my ass handed to me by the RC passages. So I decided to take your advice and tackle each paragraph like a LR stim and go real slowly. It's worked, my score went up and I have a better understand of the passage but it's taking me waaaaaaay to long. How long should I keep going slow?

Thanks for the help

I wouldn't worry too much about timing until you get 3 weeks out from the test. Definitely work on it and practice so you get faster, but don't start actually worrying about it and focusing on it until mid-May.