@dylanemein

If conservationists don’t help, monkeys go extinct.

Put it another way: if the monkeys survive, then conservationists must have helped. (If they hadn’t helped, the monkeys would be extinct!)

Meanwhile, we know that if this habitat is preserved, monkeys survive.

We can put these ideas together. The habitat preservation guarantees monkey survival, and any scenario with living monkeys is one in which conservationists intervened. So if the habitat is preserved (saving monkeys), that guarantees conservationists intervened.

Put it another way: if conservationists don’t intervene, the habitat can’t be preserved. Because if they don’t intervene, the monkeys don’t survive. And the monkeys definitely survive in any scenario where the habitat is preserved.

It is an unjustified assumption! But the stimulus makes the same kind of unjustified assumption—which is what makes this AC right!

The stimulus assumes, without justification, that the additional income from the owners' other properties will be sufficient to offset the cost of improvements.

But will the added income from their other properties really be enough to offset costs? We have no proof of that.

Likewise, will John's joy/health from exercise really be enough to offset the downsides of post-op pain? We have no proof of that either.

Both the stimulus and AC A make unjustified assumptions to reach their conclusion. Which is what makes AC A a good parallel match.

AC A does indeed make an unjustified assumption, and understanding that is central to understanding why the AC is correct. 

I think it's crucial to see that the stimulus is flawed. So the correct AC has to be flawed in the same way. 

(Not all parallel flaw questions explicitly name that the stimulus is flawed, but we still have to match the flaw.) 

Stimulus:

• Owners believe that the cost of improvements will not be offset by the new income they generate.

• But the improvements will have a secondary effect, raising additional income elsewhere.

• Conclusion: The owners should make the improvements. 

This argument makes a necessary assumption: together, the added income from the improved apartments and the added income from neighboring apartments will be enough to offset the cost of improvements.

But that isn't stated anywhere. The assumption is unjustified.

What if, the total income boost across all the owners' buildings will be $1 million, but the improvements will cost $5 million? Then they're still out $4 million.

If this were a necessary assumption question, this assumption would be the most important characteristic of the argument. So we need an AC that makes a similarly unjustified assumption. 

Enter AC A:

• John doesn’t want to invest in knee surgery because the pain it will cost him will not outweigh the pain he currently experiences. 

• But the surgery will also enable him to exercise again.

• Conclusion: he should get the surgery. 

This argument makes the same kind of necessary assumption that the stimulus made: that together, the benefit of getting exercise and curing whatever pain John currently has will be enough to offset the physical cost of a painful surgery. 

But, as with the stimulus, that isn't stated anywhere. The assumption is unjustified.

What if the surgery is so excruciating that John will never mentally recover? What if John doesn’t actually like to exercise that much? What if he has a week to live and won’t really get to enjoy the benefits of having had the knee surgery, so doesn’t want to spend his final week in post-op agony? Etc, etc.

The argument in AC A has the same necessary assumption flaw as the stimulus. That’s what makes it the right answer. 

I didn’t like E because of the assumption that the El Niño was in 1997. The stimulus doesn’t say in what year the El Niño occurred. The most recent El Niño might have been in 96 or 95. And we don’t even know that the most recent one is the one at issue.

But the AC is protected by the hypothetical “if,” which allows it to assume a year for the relevant El Niño and still be the correct answer.

I still think this weakens the AC. It could be that the relevant El Niño was in 95, then the forest fires happened in March 97, and the El Niño of 97 began that April.

But given the reasons for eliminating D, I guess E is the better answer.

Two ways I think about this:

1: Intuitively. It's possible that Xavier and Miranda have more thoughts than they're sharing here. For example, "Look, I mean the place had a tiny menu, a terrible chef, and bad service. The owner is notorious for bankrupting every business they touch. But my god, they didn't even have indoor seating! Of course they failed!"

Neither of them says that the lack of indoor seating was the only failure of the restaurant. It's just the one that they discuss here.

2: In formal logic terms, this can be articulated as a confusion of necessity for sufficiency.

We know from the dialogue that they believe...

"If no indoor seating -> then not successful."

And we can derive the contrapositive. They believe...

If successful -> then indoor seating.

The contrapositive would allow for C to say the reverse of what it says. Namely, "If the new fast food place had been successful, it would have featured indoor seating."

In that correct statement, indoor seating is considered necessary for the restaurant to succeed.

But the dialogue doesn't suggest that indoor seating is sufficient. We can't be sure that indoor seating alone would make success likely.

As the intuitive version demonstrates, there are plenty of other factors that might have made success super unlikely, even if they did have indoor seating. So the dialogue does NOT clearly indicate "If indoor -> then successful."

To me, this teaches a lesson about how to handle paradox 50/50s where both ACs require assumptions. I see a 50/50 between A and B.

The central questions raised by the paradox: If babblers are usually unnoticed by predators until they bark, what additional benefit does barking provide? And why is that benefit worth the additional risk—especially after most members have made it to safety? 

A. Babblers fly faster than their prey. 

Keep open. This does explain why babblers accept the added risk of barking: after giving up their location, they can escape easily. But it doesn’t explain why babblers bark in the first place: what’s the added value of barking? 

We can solve the latter question with assumptions. For example, maybe they bark to warn comrades who haven’t noticed the predators.

But that means we’re using an assumption—bark as warning—to do the most important work in resolving the paradox: answering “what additional benefit does barking provide?”

B. Predators are intimidated by babblers’ large numbers.

Keep open. This answers the biggest question—what additional benefit does barking provide? But it doesn’t answer why the added risk is worth the added benefit. Namely, why do babblers risk barking when they get plenty of protection via camouflage without it? Why not just stay unnoticed?

We can answer that with educated guesses, including: to account for the rare cases when predators do spot them (premises only say that babblers are “usually”/“generally” unnoticed), and/or to protect slower babblers who can’t get to safety quickly (premises only say that “most” babblers get to safety quickly). 

C. There are lots of predator species.

Eliminate. This only helps resolve the paradox if different predators have different dynamics with the babblers visa-vis spotting them, hearing them, etc. But the premises have already lade out what predators can and can’t do, and LSAT rules dictate that we have to stipulate that those premises apply to all predator species.  

D. Predators have good eyesight, weak hearing.

Eliminate. All of D’s potential explanatory power is robbed by the premises. If predators’ good eyesight meant that babbler camouflage didn’t work, then this would be helpful. But we know from premises that camouflage works. Likewise, poor hearing could explain why babblers aren’t afraid that their barks will be heard, but the premises already established that predators do hear and locate babblers by their barks. 

E. Other animals are nearby, vulnerable to the same predators.

Eliminate. This is attractive because it suggests that babblers bark to help the other animals, but since we’re talking survival of the fittest here, E requires an additional assumption that babblers get an evolutionary benefit from protecting neighbors. And while that’s plausible, it would take some serious evidence. This requires too big an assumption.

So 50/50 A and B.

Both require assumptions to work. But they require those assumptions in different places. AC A requires an assumption to explain why babblers bark in the first place. AC B explains why they bark, but requires an assumption to explain why the benefits of barking outweigh the risks. 

Lesson:

In paradox 50/50s, if the paradox raises a compound question ("what additional benefit does barking provide, and why is the additional risk worth that added benefit?"), the right answer is the one that answers the more essential part of the compound ("what added benefit does barking provide?"). 

I saw it this way too during the test. On reread, I see that they were using vicinity as a word that would be maximally inclusive, capturing both the parking area in front and the surrounding street parking. But it sure is unclear!

I came here to find someone else with this objection, hoping someone would have explained why it's wrong. I was stuck for a while trying to figure out a way out of it. As you say, E could be interpreted to mean "Overlooks the possibility that Millennials and Zoomers will turn out to vote more in the future while Xers and Boomers will vote less."

Ultimately, I'm realizing that if you buy the idea that the conclusion's phrase "are becoming increasingly" is a statement about the present rather than a statement about the future, then E doesn't work regardless of how "age groups" is interpreted.

Regardless of whether E's "age groups" refer to Zoomers/Millenials or to generations yet unborn, E is still making claims about the future. And, in JY's reading of the conclusion, the future is not up for discussion here.

Incidentally, I found it a tough sell that the conclusion was not talking about a continuous process stretching into the future, but I do ultimately think that JY's right. If we had a conclusion that said "The leaves are turning more yellow, red, and brown with each passing day," we wouldn't assume that the leaves will keep trending that way forever. We'd assume that this claim is limited only to the present season.

I had this concern too. "Some" airtime implies that both pop and classical will be played.

What clinched it: The stimulus did not say "All Pop or All Classical or Some of Both." It didn't have all three of these options, it only had two options.

Since none of the ACs capture "Some A or All B," I had to let go of the "some" distinction and accept that, in this scenario, LSAT must be interpreting "Some-Pop" as a single concept ("A") that's an alternative to All-Classical ("B").

Another way of explaining why C doesn't work:

Stimulus: Assumes that one disease must do it all alone. But actually multiple diseases can get the job done together.

Answer B: Assumes that one person must do it all alone. But actually multiple people can get the job done together.

Answer C: Assumes that one restaurant must do it all alone. And indeed, getting dinner "together" does require one restaurant to do it all alone.

C has other flaws, like not accounting for compromise or non-local restaurants or alternatives to going home. But C's flaws don't match the stimulus.

If your goal is to get dinner together, a patchwork of different restaurants won't work. (Whereas a patchwork of different diseases or a patchwork of different DIY-ers will work in the stimulus and B.)

@sunday9t9t677

It's a grammatical error in the test. (Though the grammar error doesn't invalidate the answer.)

The subject of the sentence is "judgments." Shortened to remove all its adornments and subordinate clauses and phrases, the sentence as it stands would read "Judgments is harsh," which reveals the broken subject-verb agreement. It should be "Judgments are harsh."

"Most" is merely a quantifier, and doesn't affect whether a plural or singular verb should be used. Here too, a simpler sentence is helpful for revealing what the grammar ought to look like:

Correct: "Most answer choices are written grammatically."

Incorrect: "Most answer choices is written grammatically."

The same goes for other quantifiers.

Correct: "Ten percent of answer choices are wrong."

Incorrect: "Ten percent of answer choices is wrong."

If the object of the preposition in the quantifier phrase is singular, then you'd get a singular verb:

Correct: "Ten percent of the population is infected."

Incorrect: "Ten percent of the population are infected."

Having said that, while quantifiers don't make plural subjects singular, there's a similar situation where this does happen, which makes things super confusing: A single group with many members would be considered singular. For example: "That bouquet of flowers is pretty." The subject is bouquet, not flowers. And bouquet is singular.

I’m thinking this too. /N or /O > /M would be “If either N or O is not adopted…” or “If N is not adopted, or O is not adopted…”

But it seems to me that “If N or O is not adopted” should be represented as you said, or as /N & /O > /M.

Example: “If I don’t shop or order takeout, I won’t have food for dinner.” I would have to neglect both shopping and ordering to miss out on dinner. Neglecting just one or the other would not be sufficient. I could miss shopping but still order. So…

/(Shop or Order) > /Dinner

Or

/Shop & /Order > /Dinner

But it wouldn’t follow to say

/Shop or /Order > /Dinner

To make the latter work, a better example would be “If I don’t have time to cook or I don’t have time to eat, I won’t be able to have dinner.” that would get:

/Cook or /Eat > /Dinner — if either one is negated, I miss out on my chance for dinner.

Agree. IMO, answer B should not suggest that daytime flocking is evidence "given" to support feasibility.

The small daytime flocking groups are presented as an obstacle that any clustering hypothesis would have to overcome:

"...while such small groups alone could not maintain such high body temperatures..."

That's a concession, and according to the passage, the hypothesis would have to expand to explain away how larger clusters could form despite these patterns.

My think-like-the-LSAT takeaway is:

(a) I guess, even on RC, they care more about logical force than content. And answer B is definitely the best match for the logical force of the clustering hypothesis (ie, that it's merely "feasible."). Even if the full text of B doesn't reflect a close read of content.

(b) Maybe their reasoning was that if kinglets already flock in small groups, it contributes to the feasibility that they might form even larger groups at night? Namely, the fact that they flock at all makes it more feasible than if they didn't flock by day? The passage didn't support that reading, but it does sound like a plausible interpretation...