LR Problem Set #1, Q: 11

[moshei24]

Hi!

Would you mind explaining this question? I see why answer choice B works, but I don't see why answer choice D doesn't. Why can't slowing deforestation down be consistent with the politician? He says that they need to stop deforestation in order to save the koala. Does the LSAT assume that that is the only way to stop the extinction? That anything less than completely stopping deforestation won't prevent the extinction?

Thanks!

[Adam Tyson]

You've got the answer already, moshei: Answer choice D, slow deforestation and the koala survives, IS consistent with what the politician said, but we are looking for an answer that is INCONSISTENT with what he said. We want something that can be true in light of the biologist's claim, but cannot be true if the politician's claim is true. That's why B works - the politician is saying that if we stop deforestation, the koala will survive, and B contradicts that, while D does not.

Sometimes it's just about a careful reading of the question stem. You already knew that D was consistent with the politician's claim, but you forgot or overlooked that that's what made D a wrong answer. That can happen to the best of us, especially when we are looking for something counterintuitive like this (where a "good" answer is wrong and a "bad" answer is right). Beware those kinds of situations, and be extra careful in your analysis.

Adam M. Tyson
PowerScore LSAT Instructor

[moshei24]

Looking back at this question, I think that I asked the wrong question. When I first had trouble with the question, I think I had trouble understanding why B was right, and when I looked back at it, I forgot what I was confused about. Sorry.

How is B consistent with the biologist? Oh wait, I think I see why it makes sense. Because the biologist says this:
Forest continues to disappear at current pace --> koala extinct

It would be a mistaken negation to say that:
Forest does not continue to disappear at current pace --> koala survives

And for that reason, it is consistent with the biologist's claims for deforestation to stop and the koala to become extinct. It doesn't have to happen, but it is a possibility.

So this question is kinda a must be true / CANNOT be true all in one?

[Adam Tyson]

More like a Could Be True/Cannot Be True combo question. In light of what the biologist said, the answer could be true (doesn't have to be, but could be - that's what we mean when we say "is consistent with", usually), and in light of what the politician said it cannot be true (or, if it's true, it disproves him - in either case they cannot co-exist and are thus inconsistent).

Adam

[moshei24]

Thanks!

[Dave Killoran]

Hi Moshe,

Let me jump in and second Adam's answer, and then use your question to make a separate point about the LSAT.

One of the reasons I love this question is because the question stem references the idea of "consistency." The word consistent is one that means something a bit different on the LSAT than it tends to be used in real life.

In real life, most people use consistent to mean agreement. Thus, these two statements would be inconsistent to most people:

• Statement 1: All flowers are yellow.
  
  Statement 2: My house is purple

In real life, typically people want to see an agreement between two statements to call them consistent. If they don't directly agree, then most people say they are inconsistent.

The LSAT works differently, and uses the logical definition of consistency. The logical definition of consistent is that it means "could be true," and that inconsistent means "cannot be true." Thus, the two statement above would be considered consistent on the LSAT.

Most of the time this difference isn't an issue because consistency rarely appears on the test, but it becomes one when a question uses that concept, as is the case here.

So, what are the operational effects of the LSAT meaning of consistent? Well, the first thing to consider is that millions of statements are consistent. Just about any two statements will be consistent, as long as they don't contradict each other. Inconsistent statements must contradict each other. Thus, when this particular question stem asks for what is consistent with one statement but inconsistent with another, you shouldn't worry about finding the consistent part because most of what you see will be consistent. Instead, search directly for the answer that is inconsistent, because it will have a very specific characteristic of contradicting the politician's statement.

In this case, the politician said:

D SK.

The answer we need has to contradict that, which would be:

D SK.

That's precisely what (B) says (and, as noted already, that answer is consistent with what the biologist said).

Great LSAT question--one of my all-time favorites. Thanks!

[Checkmate]

Hi Dave,

Great explanation, now that i look back, i was too busy making sure that the correct answer choice needs to be consistent with biologist's claim, not paying much attention to the inconsistent part.

[biskam]

out of curiosity, would D be consistent or inconsistent with the biologist's statement? To be inconsistent, a statement would have to be that "deforestation continues at present rate, but koala is not extinct." Since that isn't what's happening in D (the sufficient condition is entirely different), I'm guessing it could be consistent since as dave said there's a multitude of ways for 2 things to be consistent, but one narrow way for it two things to be inconsistent.

and D would also be consistent for the politician for the same reason, right? His statement opens up the possibility for other reasons, for other sufficient conditions that allow the koala to survive.

[Eric Ockert]

Hi biskam!

You are absolutely right. Answer choice (D) would be consistent with both of their statements. Neither one of them really speaks to what happens if deforestation is slowed. The biologist only speaks of what happens deforestation continues at its present pace. The politician only speaks about what happens if deforestation is stopped. Slowing deforestation would show that it is not continuing at its present pace and also that it might be stopping. In either case, that would not be enough information to activate either one of these rules. And since neither of the rules necessarily applies to answer choice (D), then it does not violate (it is not inconsistent with) either one of them.