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

[winnatech]

Hey BP,

I have two questions:
1. On PT 41 S3 Q11. I was stuck between A and D. Here was my thought process:

Premise: Investment --> rise standard of living
Conclusion: rise standard of living --> investment.

So I can see the sufficient and necessary flip. When I looked at A, I saw ~investment --> rise standard of living. Wouldn't this indicate the flaw, since the author's conclusion (taking the contrapositive) is ~investment --> ~rise standard of living? I would have the sufficient without the necessary.

It seemed that (D) had the same idea, except it was more straightforward. It has rise standard of living --> ~investment. Again, the sufficient without the necessary (when compared to the author's conclusion).

So why is (D) the correct answer?

2. PT39 S4 Q23.
I diagrammed it as
Premise: maximum total utility assured --> pure free market economy
Conclusion: ~pure free market economy --> ~most likely to bring maximum total utility.

So I can see the missing link as
~maximum total utility assured--> ~most likely to bring maximum total utility.

(D) is the right answer but has the opposite of the missing link. It says maximum total utility assured--> most likely to bring maximum total utility. Why is the answer choice a flip of the actual missing link?

Thanks!

[15chocolate]

Hi bp, thanks for the reply!! Let me ask some more questions...
So, since I take about 3:30 min. to read, I guess I should not take notes right? At least not too much, maybe just circling...I write some words and numbers on each paragraph, and sometimes for taking notes, I read the same sentence twice. (and it takes me more than 4:00 min. I guess...and for some Qs go back to the passage) Do you take any notes?

Also...I just noticed when I read the passages I lose my concentration from passage 3 or so. (or even in the middle of the passage...)
Do you have any advice to maintain concentration without losing interests?
I think this is one of the causes make me run out of time.

By the way, how long do you spend on each question? Would you recommend to read all answer choices or once I hit the correct one (which I think) should I move on to the next question?

I can also tell you what they're going to do in answer choices to try to confuse me.

How would you know how they make incorrect answers? I only notice they use opposite idea/extreme argument/does not answer the question or partially wrong...

Again, thanks for the advice, they're great!

[bp shinners]

Hey BP
What do you do if you can't understand a theory or hypothesis mentioned but in second part of the paragraph has a "however". Pt 19 sec 3 passage #3 mentions 3 theories "time line" "species energy hypothesis" and a third hypothesis. In each of them they talk about the theory and latter in the paragraph say 'however". My question is, if I don't understand the first part listed in the theory can I use the "however" and information coming afterwards to help me understand the first part? It didn't work so well for this passage.

"The time line theory says ________. However, _________"

Thanks BP

Yep, definitely! In that passage in particular (and in other passages that follow this theory), the "however" will give you reason to question the theory. This is why each of those three theories have a "however", and then we go on to a theory that the author actually thinks is supported.

So how can you use the "however" to figure out the first part? Well, the however is going to be the information that the theory can't account for. Whatever the theory says, that "however" falls outside of it. If you can figure out the "however", then you know a piece of information that hurts the theory. It should give you a foothold to understand the underlying theory.

[bp shinners]

Open.

[tuffyjohnson]

It's roughly 6 weeks until the big day and I have focussed exclusively on my weekness (LG) this far. 140 hours. I still cannot get to that 4th game. Is that honestly ever going to change at this point? Should I start thinking seriously of delaying until OCT or just jump straight into LR now and hope that LG will continue to improve from now until JUNE? The accuracy is there it's the timing in LG that's killing.

Edit: and sometimes only through half (depending on how hard the section) of the 3rd game.

[bp shinners]

It's roughly 6 weeks until the big day and I have focussed exclusively on my weekness (LG) this far. 140 hours. I still cannot get to that 4th game. Is that honestly ever going to change at this point? Should I start thinking seriously of delaying until OCT or just jump straight into LR now and hope that LG will continue to improve from now until JUNE? The accuracy is there it's the timing in LG that's killing.

Edit: and sometimes only through half (depending on how hard the section) of the 3rd game.

Have you done anything specific to work on timing? Are you spending an equal amount of time on everything, or more time on the setup/questions/one or two questions? Do you go back to see if your work is the most efficient work you can do to get to the answers? Do you go back and try to answer the absolute/global questions with just your setup and the rules?

[tuffyjohnson]

It's roughly 6 weeks until the big day and I have focussed exclusively on my weekness (LG) this far. 140 hours. I still cannot get to that 4th game. Is that honestly ever going to change at this point? Should I start thinking seriously of delaying until OCT or just jump straight into LR now and hope that LG will continue to improve from now until JUNE? The accuracy is there it's the timing in LG that's killing.

Edit: and sometimes only through half (depending on how hard the section) of the 3rd game.

Have you done anything specific to work on timing? Are you spending an equal amount of time on everything, or more time on the setup/questions/one or two questions? Do you go back to see if your work is the most efficient work you can do to get to the answers? Do you go back and try to answer the absolute/global questions with just your setup and the rules?

Have you done anything specific to work on timing? Not really other than drill and review missed inferences.

Are you spending an equal amount of time on everything, or more time on the setup/questions/one or two questions?

Do you go back to see if your work is the most efficient work you can do to get to the answers? No.

Do you go back and try to answer the absolute/global questions with just your setup and the rules? Nope.

[jmjm]

pt-36, rc:
Q2: Other answer choices (AC) in addition to the credited (c) can be argued to contain attributes that author has dismissed.

The author never states that discrimination along these lines means that you don't have a community. That's an example of why a specific "community" shouldn't count as one, and it's meant to support the actual criteria offered by the author.

thanks BP good stuff. It's taking me quite some time to get used to lsat way of thinking due to my occupational hazard of engineering profession. I have taken around 45 RC sections and about 30 PTs but still making lots of mistakes, -3, -4 per section primarily due to time constraint. Is there room for improvement with more tests?
Not sure if for lsat less-is-more in that as one gathers life experiences they tend to think of problems designed for a specific assessment from a variety of viewpoints that at times is not needed nor required and can even be detrimental to solving the given problem quickly.

[bp shinners]

thanks BP good stuff. It's taking me quite some time to get used to lsat way of thinking due to my occupational hazard of engineering profession. I have taken around 45 RC sections and about 30 PTs but still making lots of mistakes, -3, -4 per section primarily due to time constraint. Is there room for improvement with more tests?
Not sure if for lsat less-is-more in that as one gathers life experiences they tend to think of problems designed for a specific assessment from a variety of viewpoints that at times is not needed nor required and can even be detrimental to solving the given problem quickly.

Honestly, -3/-4 average for RC sections is pretty solid. That's the section where I see most of the top-scorers from my classes losing points (and the section that I'm least likely to bet I'll bat 1000 on). So there is room for improvement, but getting -0/-1 per passage is pretty solid already.

And I think you're circling the explanation - as you get more experience, it's harder to not let that bias the way you see things. The LSAT is very much a test of taking people at their word and dealing with their arguments in the world they're living in. When you have more experience, it's harder to let it all go and just use the logic instead of the knowledge.

[lsatkid007]

Hey BP
Pt12 s1 #14. I know it's a "% cannot justify conclusion regarding definite amount" fallacy. I'm just not getting this one.

Thanks

[15chocolate]

Hi, bp
It seems like one of my posts is not answered, so let me ask this one more time...

***
So, since I take about 3:30 min. to read, I guess I should not take notes right? At least not too much, maybe just circling...I write some words and numbers on each paragraph, and sometimes for taking notes, I read the same sentence twice. (and it takes me more than 4:00 min. I guess...and for some Qs go back to the passage) Do you take any notes?

Also...I just noticed when I read the passages I lose my concentration from passage 3 or so. (or even in the middle of the passage...)
Do you have any advice to maintain concentration without losing interests?
I think this is one of the causes make me run out of time.

By the way, how long do you spend on each question? Would you recommend to read all answer choices or once I hit the correct one (which I think) should I move on to the next question?

I can also tell you what they're going to do in answer choices to try to confuse me.

How would you know how they make incorrect answers? I only notice they use opposite idea/extreme argument/does not answer the question or partially wrong...
***

Thank you

[objection_your_honor]

BP:

It's easy enough to eliminate answer choices that use the word "often" in principle-support/identify Qs when all we're given in the stimulus is a sample size of one — often implies regularity and frequency. But doesn't "tend" do the same?

See PT33 S1 Q18 as an example of the use of this word.

Can we infer that the use of "people tend" is justified here because of the stimulus' "it is no wonder..."? If that is the case, would "people often" be just as justified in answer choice A?

Trying to determine when the word does and does not disqualify an answer choice. I'm contrasting it with PT37 S2 Q18. TCR is more satisfying here because it doesn't overreach.

[bp shinners]

Hey BP
Pt12 s1 #14. I know it's a "% cannot justify conclusion regarding definite amount" fallacy. I'm just not getting this one.

Thanks

Not sure what else there is to get here if you get that it's a % vs. amount fallacy. My conclusion is about an absolute number (how many quit), and my premise is about a percent. If I make some numbers up, you see the problem:
Say there are 200 part-time teachers and 100 full-time. If 25% of the part-timers quit, that would be 50 teachers. If 33% of the full-timers quit, that would be 33 teachers. That is at odds with my conclusion. In order for the 25% to be a smaller number than the 33%, I need to know that there aren't more part-timers than full-timers (you can calculate the exact ratio if you want; it's not worth it). That's (D).

[bp shinners]

Hi, bp
It seems like one of my posts is not answered, so let me ask this one more time...

Sorry for missing it!

So, since I take about 3:30 min. to read, I guess I should not take notes right? At least not too much, maybe just circling...I write some words and numbers on each paragraph, and sometimes for taking notes, I read the same sentence twice. (and it takes me more than 4:00 min. I guess...and for some Qs go back to the passage) Do you take any notes?

I honestly think anyone who doesn't take notes is shooting themselves in the foot. So much of RC is being able to quickly navigate through the passage so you can find the quotes that support your answers. At the very least, you should have the author's attitude underlined and a tag describing the role of each section of the passage.

Also...I just noticed when I read the passages I lose my concentration from passage 3 or so. (or even in the middle of the passage...)
Do you have any advice to maintain concentration without losing interests?
I think this is one of the causes make me run out of time.

There are many methods for maintaining concentration, but you have to find the one that works for you. The one I go with is I do the 8/7 question passages first, and I leave the comparative and 5/6 question passages for last. Those tend to be less dense, which makes them less mentally taxing, so you tend to drift less.

By the way, how long do you spend on each question? Would you recommend to read all answer choices or once I hit the correct one (which I think) should I move on to the next question?

45 seconds-1 minute/question. I always read all of the answer choices unless it's a specific question to which I'm 100% sure of my answer. If you don't read all the answer choices for other question types, you're much more likely to fall for a sucker choice.

I can also tell you what they're going to do in answer choices to try to confuse me.

How would you know how they make incorrect answers? I only notice they use opposite idea/extreme argument/does not answer the question or partially wrong...

Because they always use the same tricks to form incorrect answers. Other than the ones you list, they always equivocate between terms that are similar (for instance, trying to get you tripped up between parasite and pathogen, or electroreceptors and mechanoreceptors). They also try to fudge the borders between the concepts the list as discrete (such a distinct art styles).

[bp shinners]

I think you're a little off on the way you're viewing this question, based on what you're asking. For this type of question, I'm trying to find an answer that backs up the stimulus, not an answer choice that is backed up by the stimulus. So the fact that the stimulus here only gives one example has nothing to do with how strong I want my answer choice to be - I'm looking to find an answer that provides support for my conclusion, not an answer choice that is a generalization I can draw from the stimulus.

See PT33 S1 Q18 as an example of the use of this word.

Can we infer that the use of "people tend" is justified here because of the stimulus' "it is no wonder..."? If that is the case, would "people often" be just as justified in answer choice A?

We absolutely cannot infer that people "tend to" because of the example in the stimulus. Luckily, though, this isn't an inference question. It's an operation question, and, more specifically, a strengthen question. We want a principle that makes the reasoning justified, and (A) does just that. If it's the case that people tend to ignore the cons of actions that support what they're doing, then it's more likely that these environmentalists will ignore the cons of the spacecraft.

[Dr. Dre]

does "whenever" introduce a sufficient condition?

[melmoththewanderer]

Hey Shinners! I want to toss a few RC questions your way.

PT 62 S1 Q4 What's wrong with E?
PT 62 S1 Q8 What makes D better than the others?
PT 63 S4 Q23 What's wrong with E?

[bp shinners]

does "whenever" introduce a sufficient condition?

Yep.

Whenever bp shinners goes to a Meat Loaf concert, he is hit on by 50-year-old women.
BP@ML -> HO50

[bp shinners]

PT 62 S1 Q4 What's wrong with E?

Line 54-End tell me that it's best in these places, but that I can take the other conditions into account when using lichonometry ("...conditions...must be factored in."). That just tells me it's best when these don't happen, not that the usefulness is "limited to" places where it generally doesn't happen. It also tells me that I can factor in some of these conditions, thus figuring out the age even if we do have wind and shade. The "limited to" makes this AC too strong.

PT 62 S1 Q8 What makes D better than the others?

A- If the river is flooding up and down, the lichen is going to have problems - it grows on exposed rock, so at most I'll be able to tell the highest that the river reached, not the number of times it flooded.

B - Sounds like this was buried. No exposed surface = no lichen.

C - Ditto with B - it's underwater, not exposed.

E - I'm never told that rainfall affects lichen growth, so no reason to think it'd be helpful to measure rainfall.

D - Receding glacier? That'll expose rock. I can measure the size of the lichen to tell when it was last covered by the glacier.

PT 63 S4 Q23 What's wrong with E?

This is a specific reference question, so I need the AC specifically mentioned in both passages. Can you point out where you see E, specifically (not inferentially) in both passages?

[melmoththewanderer]

Thanks BP! I think I failed to draw the distinction between inference and explicit mention for the last question.

[bp shinners]

Thanks BP! I think I failed to draw the distinction between inference and explicit mention for the last question.

That'll do it. It's really important on RC to know if you're in an Inference or Specific Reference question, so make sure to check that out before trying to answer it!

[Dr. Dre]

PT 36, Section 2, Q# 10

So is an argument guilty of begging the question if it uses PART of a premise to support the conclusion — OR — must the argument use the ENTIRE premise to support the conclusion, for it to be considered begging the question?

I say this because the stimulus uses part of a P to support the C...and the correct answer maintains that the flaw is circular reasoning.

Also, can you explain E? That answer seems so perfect. . .

[nyjets2090]

Hey bp_shinners,

Worked through the BP Logic Game book. Awesome stuff in there and I'd recommend it to anybody who wants a way to learn LGs without being too bored...it's almost impossible to make a minotaur with a monocle boring...

Quick question though about conditional logic. In the first game (Dec 97, Game 4) the third rule made me think for a bit.

Would it be properly diagrammed:
N ∧ U --> ~G
(G --> ~N ∨ ~U)

Because "unless" becomes "if not", does the "and" become an "or"? I know that's the way to negate and, but was unsure if "and" becomes "or" when "unless" becomes "if not."

Sorry if that's worded poorly, I can try to reword it if that's not clear.

One more question, do you notice that games with scenarios tend to have alot of absolute or conditional questions (I notice that if they're asking more than 1 absolute question it tends to be a game with scenarios)? Or is it just better to stick with identifying scenarios by finding a rule?

Thanks.

[bp shinners]

PT 36, Section 2, Q# 10

So is an argument guilty of begging the question if it uses PART of a premise to support the conclusion — OR — must the argument use the ENTIRE premise to support the conclusion, for it to be considered begging the question?

I say this because the stimulus uses part of a P to support the C...and the correct answer maintains that the flaw is circular reasoning.

Also, can you explain E? That answer seems so perfect. . .

I hardly recognized you, Dre. But don't worry - I didn't forget about you.

Any part of a premise that expresses a complete thought is a premise itself. Sentences don't define premises - clauses do. So in the case of Cotrell, I can find the following two statements:
"Cotrell is, at best, able to write magazine articles of average quality." (the conclusion)
and
"Cotrell, who is incapable of writing an article that is better than average..."

That, by itself, is a premise - the rest of the sentence makes up additional premises (including a subsidiary conclusion). And that premise expresses the exact same idea as the conclusion, so the argument is circular.

So take-away from this: Premises aren't sentences, they're facts/ideas/statements. There could be one to the sentence; there could be many in a single sentence.

Let's look at E now - It infers limits on ability (i.e. he's average) based on a few isolated LAPSES in performance. It does infer limits on his ability, but it does so based on the fact that he must have plagiarized the few good articles he's written (the circular logic part). It's not inferring it based on LAPSES in performance - it's inferring it by throwing out the articles that were better than his average.

If E was correct, I'd need a stimulus similar to the following:
Cotrell is able to write average-quality articles, at best. The most compelling evidence for this are the few articles he wrote on beluga whales, for while the rest of his articles were fantastic, his whale articles were boring and featured factually inaccurate information.

Here, he had a few lapses in quality (the whale articles), and I'm throwing out the rest of his body of work because of those. The stimulus does the opposite here.

[bp shinners]

Would it be properly diagrammed:
N ∧ U --> ~G
(G --> ~N ∨ ~U)

Because "unless" becomes "if not", does the "and" become an "or"? I know that's the way to negate and, but was unsure if "and" becomes "or" when "unless" becomes "if not."

I didn't look up the reference, but when you change "unless" to "if not" and negate that condition, you DEFINITELY DO change "and" to "or" and vice versa. You need to negate the entire condition, which includes the conjunction/disjunction.

One more question, do you notice that games with scenarios tend to have alot of absolute or conditional questions (I notice that if they're asking more than 1 absolute question it tends to be a game with scenarios)? Or is it just better to stick with identifying scenarios by finding a rule?

It's better to stick with identifying scenarios by finding a rule.

That being said, you can use the question types to give you a hint as to how many deductions there are. If every question is a Conditional question, it's more likely that the rules won't give you many deductions (because the questions will give you more with which to work). Flipside is that Games with a large number of Absolute questions should have a lot of deductions, since an Absolute question is essentially just asking you to find a deduction anyway.

Scenarios are not quite deductions (since it's not a clever combination of rules, but rather the implications of a single possibility of a single rule), though they often rely on deductions to be filled in. So I would not use the question types to determine the existence of scenarios (I would just use my scenario-suggesting rules:
Ordering - blocks, options, arches (in that order)
Grouping - must be together, weird rules).