The LSAT Logical Reasoning Questions should be studied. Watch this video to learn and find an LSAT Tutor today.
LSAT Logical Reasoning Questions [Video Transcript]
Hi. Welcome back to Casebriefs LSAT Course Lesson Two. My name is Sean Murphy. You’ve just taken your June 2007 prep test. As I said before, don’t worry too much about your score. The average improvement for LSAT students is about 10 to 12 points. I’ve had students go up by as many as 25 points. So whatever score you got, you’re probably not going to stay in that range for very long.
Let me talk a little bit more about what that score actually means. Let’s say you got a 152. That meant that you got 63 questions right. So, 63 would be your raw score, 152 would be what’s called your scale score. And that 152 corresponds to a percentile of about 55. So that means if you got a 152, you’re better than about 55% of the other students who took the LAST. So that’s pretty good. You did a little above average.
If you can just get 10 more questions right on the entire test, so maybe 3 questions right on the logic games, 3 more questions right on the reading comp, and 2 more questions right on each of the score logical reasoning sections. If you get a raw score of 73, well, that doesn’t seem to improve your scale score all that much. It’s an improvement of 5 points to a 157. And that might not seem very dramatic. But in terms of percentile, that put you around the 75th percentile. So that actually is a really dramatic improvement. So especially if you’re in the 140s and 150s, every little improvement, every more question right, can really dramatically improve your score. So, there’s plenty of room for improvement. Even small games can really improve your chances of getting into the school you want to get into. So do your best and don’t be discouraged if you’re not improving as quickly as you would like.
But let’s start to talk about the actual test. We’re going to start out with logical reasoning because logical reasoning is, as I said earlier, the heart of the LSAT, there’s always two scored sections. You might even see three sections of it, if your experimental section is logical reasoning.
So I want you to take out your June 2007 exam. And I want you to look at section 2, number 21. So number 21, there’s a driver. There’s a short passage. Apparently, the driver saying something that’s followed by a question, and then we have the answer choices. So I’m of the mind that you should read the passage, or often we refer to the passage as the stimulus, I think you should read that first. Some other companies will tell you to read the question first because they’ll say, “Well, if you read the question first, you’ll know what you’re looking for and that will help you find the correct answer more efficiently.” I have not found that to be true. I think it’s better to analyze the argument on its own terms, analyze the passage by itself before deciding whether you’re going to strengthen or weaken or just find the flaw in it. That being said, it’s not all that important.
If you really think reading the question first works for you, that’s great. If you want to read the passage first, that’s what I’d like, that’s also great. It’s all about getting to the correct answer. So I’m not going to tell you exactly how to do every kind of question, unless it’s a logical issue, unless there’s real questions of logic that determine how you should approach a different question. So I’m not going to tell you exactly the technique to use. I like to read the passage first, others read the questions first, and that’s okay.
So let’s look at the passage first, though. The driver says, “My friend say, I will one day have an accident because I drive my sports car recklessly. But I have done some research, and apparently minivans and larger sedans have very low accident rates compared to sports cars. So trading my sports car in for a minivan would lower my risk of having an accident.”
Now the question stem, “The reasoning in the driver’s argument is most vulnerable to the criticism on the grounds that this argument…” And then we have the answer choices. So clearly the LSAT authors don’t like this argument. I hope that you didn’t like it before you looked at the question stem because it’s actually not that intelligent.
It’s the first step of reading any argument, is to understand whether it’s a relatively decent argument or a bad one. Even if you liked it, even if you think that this driver will be perfectly safe once he or she buys a minivan, you should then look at the question stem and say, “Oh, well, the LSAT authors did not like this argument, so I’m going to have find some weakness in it. I’m going to have to choose an answer choice that finds its weakest aspect.”
So the LSAT thinks this is a bad argument. Why? Because the evidence does not fully support the conclusion. On the LSAT, we never get to the right answer by doubting the evidence. We have to doubt the relationship between the evidence and the conclusion. Now, let’s talk a little bit about what portions of this argument are the evidence, and what portions of this argument are the conclusion.
We see the word “so” in the last sentence. That word indicates that we’re dealing with the conclusion. The other information, the research the driver has done, that supports the driver’s conclusion. The first sentence about what the driver’s friend say, it’s really not that important. It’s not real evidence. So really, we’re concerned with the relationship between the evidence and the conclusion. The evidence is that it’s based on the driver’s research, “Minivans and larger sedans have a very low accident rate compared to sports cars.” So there’s a low accident rate for minivans and larger sedans and more boring cars compared to fancy sports cars. The conclusion, if this particular driver trades his sports car for a minivan, he’ll be a much safer driver.
Now a lot of us just intuitively realized that that’s a bad argument. We probably think that this driver is kind of a reckless driver himself, and so what car he drives isn’t really going to determine how he drives. I think a lot of us can see that. But the difficulty on an LSAT question is translating that intuition into an answer choice.
Now, we’re asked to describe the flaw. This make a criticism at the point where this argument is most vulnerable. So we understand that it’s really not okay to take this evidence of minivans having a lower accident rate and infer or conclude that the minivan will cause the driver to drive more safely. The driver gave us evidence that’s called a correlation. A correlation is just a relationship of different factors. “If you study more for the LSAT, you’ll get a better LSAT score.” We call that a correlation.
Now, most of us would probably think, “Well, if I study more, that’s going to cause me to get a better score,” and you probably will be right. But on its own, a correlation does not imply causation. Just because two factors are related in some statistical manner, doesn’t mean that one causes the other. In this case, minivans might have a lower accident rate, but it’s probably not the minivan itself causing the lower accident rate. It’s probably the fact that safer drivers, people with families tend to buy minivans compared to more reckless individuals who tend to buy sports cars.
So, now we look at the answer choices and determine which of them actually describes that flaw of taking a correlation, and thinking that it means causation. When we look at answer choice A, “infers a cause from a mere correlation.” Well, that’s exactly what I said. And so you might think, “Well, you’ve know the answer already, Sean, so you’re just telling us in advance, and that’s not fair. And I don’t want to take this course anymore.” But the point I would make is that when you get really good at analyzing arguments, you’re going to read this argument and you’re going to see right away that the driver is taking a correlation and thinking that it implies causation. You’ll see arguments like this again and again as we study more and more LSAT questions. And you’ll see right away that that’s what this guy is doing and it’s wrong.
Let’s take a look at the other answer choices. Answer choice B, “relies on a sample that is too narrow.” That actually might be true. We don’t really know anything about the research this driver did. Maybe he did really comprehensive research and looked at minivans in all 50 states and in all different types of demographics and kinds of drivers and whatsoever, maybe. But we just don’t know. And we’re not going to choose the flaw that might be there or might not be there. We want to choose an answer choice that describes definitely something that happened in this argument. And definitely the driver went from a correlation to a causation.
Maybe B is true but B gets into the realm of doubting the evidence. And we generally don’t want to do that on the LSAT. We will accept the driver at his word. We want to say, “Yes, driver, you’ve done great research. Your evidence is solid.” But still, it doesn’t prove the conclusion. We get mileage on the LSAT by doubting the conclusion, not doubting the evidence. Because then, it’s just a free-for-all. Then, we can doubt anything in the passage and there’ll be no structure. You accept the evidence but still doubt the conclusion, and that’s how you’re going to get to your correct answer.
Let’s take a look at the rest of these answer choices. Answer choice C, “misinterprets evidence that a result is likely as evidence that the result is certain.” Well, definitely the driver is pretty certain that the minivan will him a safer driver, but the evidence doesn’t even prove that such a result is likely. The evidence just proves that there’s a correlation and there’s probably no causal relationship here. So C is describing something that’s not even there in the argument so it can’t possibly be right.
D, “mistakes a condition sufficient for bringing about a result for condition necessary for doing so.” That’s kind of confusing. Sufficient and necessary, what are those words actually mean? We’ll discuss them a lot later in this lesson. But for now, we can be safe to say that that didn’t happened here.
E, “relies on a source that is probably not well informed.” Again, this is a lot like B, it’s possible. But we just don’t know anything about the author’s sources. We have no real reason to doubt the sources. But we have a very obvious reason to doubt the author’s conclusion. So that’s why we’re going to stick with B.
Let’s look at another problem. From the same section, Section Two in the June 2007 test, number 17. “There’s a hospital executive. At a recent conference on nonprofit management, several computer experts maintained that the most significant threat faced by large institutions such as universities and hospitals is unauthorized access to confidential data. In light of this testimony, we should make the protection of our client’s confidentiality our highest priority. The hospital executive’s argument is most vulnerable to which of the following objections?”
So again, we’re looking at a bad argument. We’re looking at the conclusion, looking at the evidence, and thinking, “Why is this not good? Why does the evidence not proved the conclusion?” First step, as always, is to identify the conclusion and the evidence. So the conclusion is the last sentence, at least the last sentence after the comma, “We should make the protection of our client’s confidentiality our highest priority.” Now there aren’t really any conclusion keywords here. We’ll discuss more about conclusion keywords and analyzing more in depth how to break apart an argument in Lesson Four, when we talked about main point questions.
But for now, we’ll identify this conclusion and we can identify it in couple of ways or by looking at a couple of pieces of the argument. First of all, the word “should”. It’s telling us what we should do, what is the right way to think, what is the right course of action. Often conclusions are like this. This is actually what we call a prescriptive statement. It’s telling us what we should do in the same way that a doctor prescribes a certain drug. And those kinds of statements are usually in the conclusion. This conclusion is supported by what’s called descriptive evidence. Don’t worry too much about the terminology. Today, we’re just looking at some bad arguments, and then we’ll be looking at some other material later on the lesson. But just for now, a prescriptive statement, if it’s in the argument anywhere, there’ll definitely be one in the conclusion.
Also the phrase that introduces the sentence, “in light of this testimony,” that’s telling me that what came before proves what comes after. So, what comes before the last sentence is the evidence, the last sentence itself is the conclusion, and now, let’s think about the relationship between the evidence and the conclusion.
The evidence, “Several computer experts maintained that the most significant threat faced by large institutions such as universities and hospitals is unauthorized access to confidential data.” The conclusion, “We should make the protection of our client’s confidentiality our highest priority.” Well, computer experts are saying that unauthorized access to data is the most important thing a hospital needs to worry about. The conclusion, and this is a conclusion made by a hospital executive is that, “We should make protection of our client’s data, or their confidentiality, our highest priority.”
Now, I don’t know about you but when I go to a hospital, my first concern is not dying. And then maybe I’ll worry about whether or not hackers out in the world figure out what kind of illness I have. But the first concern I have is whatever sickness I have being relieved. Also hospitals have, in addition to patients worried about not dying, they’ve got nurses and doctors who have their careers there. They’ve got legal issues to worry about. There’s a lot of issues that a hospital has to deal with that might not be lesser than the concerns of the computer experts.
So what we should be thinking when we see this argument is that, “Well, the computer experts have their concern, but that might not be the concern of the entire hospital.” And I think that’s about enough analysis to do before moving on to the answer choices. Let’s take a look at them.
Answer choice A, “The argument confuses the causes of a problem with the appropriate solutions to that problem.” Well, there’s nothing about a cause and effect here. There’s nothing about what causes confidential data to leak out, so that’s not relevant to this argument. Answer choice B, “The argument relies on the testimony of experts whose expertise is not shown to be sufficiently broad to support their general claim.” Well, we’ve looked at computer experts, but then we thought maybe a hospital has broader concerns than just those of the computer experts, than just those of protecting data. So B is the correct answer.
On the LSAT, it’s okay to rely on expert testimony for evidence. If those experts are relevant to the argument at hand. Now, this argument deals with the concerns of a hospital, in general. And so we can’t just look to computer experts for that information. We need to consult doctors and nurses and patients and lawyers. We need to be concern with the large range of expert testimony. So just taking the computer experts, and thinking that they know what a hospital should do, that’s a flaw in the LSAT. So B is going to be our correct answer.
Answer choice C, “The argument assumes that a correlation between two phenomena is evidence that one is the cause of the other.” Well, that’s interesting because that was the right answer. A correlation versus causation flaw that was correct in the question we just did. So what you can begin to see is that similar flaws repeat on the LSAT sometimes is correct answers, sometimes is incorrect answers. So if you understand what a correlation versus causation flaw is, you’re going to be really well equipped to choose that answer choice when it’s correct, but also eliminate it very quickly when you know it’s not the particular flaw here. Even if you are confused by the argument and you didn’t really see that it was an expert flaw, if you’re familiar enough with that general correlation causation flaw, you can pretty easily see that it’s not that in this argument so you’d be really well equipped to eliminate answer choice C.
D, “The argument draws a general conclusion about a group based on data about an unrepresentative sample of that group.” I have no indication that these computer experts are unrepresentative of computer experts, in general. This gets into attacking the evidence which is something we generally don’t want to do. So we’re going to eliminate D because we have no indication as to whether or not these computer experts are representatives. Even if they are, it’s still about argument. If they’re not representative, I suppose it’s a worse argument. But we’re looking for the flaw that’s in the argument. We don’t want to try to project too much into issues that are just not simply discussed here.
Answer choice E, “The argument infers that a property belonging to large institutions, belongs to all institutions.” There’s nothing about all institutions. We have one issue up for discussion, that’s the concerns of a particular hospital. So E is describing something that just doesn’t occur in the argument, so it’s incorrect. Once again, the correct answer is B because the argument move from the testimony of one small group of experts and made a conclusion that should’ve included consideration from experts in many different fields. We’re generally going to refer to that as an expert flaw in the future. We’ll discuss more about different kinds of flawed reasoning when we get to the lesson on flawed reasoning questions and that’s Lesson 10.
Now, you might have noticed that I relied a bit on common sense earlier. I was thinking, “Well, computer experts don’t really represent a hospital in general.” A hospital, as we know, has other things going on that don’t necessarily relate to the protection of patient’s confidential data. Now, those of you that might have taken another LSAT course, you might have an objection right here. You might say that, “Well, my teacher told me that common sense plays no role on the LSAT, that the real world doesn’t matter, that only the passage is relevant.” Well, that’s just not really true on the LSAT. The LSAT is a reality-based test. It’s pretty much based on the real world that we all exist in. If we weren’t able to use our commonsense, we might not have seen that this is a flawed argument. If we didn’t have that intuition that computer experts don’t really represent the goals of a hospital as a whole, we might not have seen that the argument was flawed and we might not have chosen answer choice B.
What students almost never do is actually read the introduction to the logical reasoning section. And that’s understandable because you get to the section, you’ll only have 35 minutes. You don’t want to read the instructions. You think you know instruction so you’re just going to go on to the questions. But it’s actually enlightening to read that introduction now when we’re not so concerned with getting everything done in 35 minutes. So let’s take a look at that introduction. You can turn to the first page of whatever logical reasoning section you’re looking at.
“The questions in this section are based on the reasoning contained in brief statements or passages. For some questions, more than one of the choices could conceivably answer the question. However, you are to choose the best answer that is the response that most accurately and completely answers the question.” Now here’s the interesting part. “You should not make assumptions that are by common sense standards, implausible, superfluous, or incompatible with the passage. After you’ve chosen the best answer, blacken the corresponding space on your answer sheet.”
So the instructions are telling you that, yeah, you can’t make assumptions that are by common sense standards, unbelievable, or dumb, but you can use your basic common sense on the LSAT. Obviously, the passage is more important than whatever is going on in your head. Everything should be based on the passage itself. But you can use your own basic understanding of world to say, “You know what, computer experts aren’t really representative of a hospital’s interest, as a whole.” So don’t think that the passage is a world onto itself, and that the world out there just doesn’t matter. The LSAT is a reality-based test. And it uses science from the real world, it uses literary analogies from the real world that we all live in. So, don’t think that you can’t make any very basic assumptions when taking the LSAT. The best kind of LSAT prep takes what you are already know about the world, about doing logical analysis, and refines it. Makes it more precise, makes it better, teaches you about the real meaning of specific words that are really important on the test. But you do absolutely have to use your own intuition, your own common sense.
Let’s take a look at a question from section 3 of this test, from June 2007, section 3, number 25. “Some anthropologists argue that the human species could not have survived prehistoric times if the species had not evolved the ability to cope with diverse natural environments. However, there is considerable evidence that Australopithecus afarensis…” My latin pronunciation has really fallen by the way-side since high school, I’m sorry. “…a prehistoric species related to early humans, also thrived in a diverse array of environments, but became extinct. Hence, the anthropologists’ claim is false.”
This is a very common kind of argument structure where we’re introduced to an idea. The idea that’s some anthropologists argue. And the conclusion is a rejection of that idea. What the anthropologists said was wrong is basically the conclusion. We can see the key conclusion word “hence.” That often introduces conclusions. So basically, the anthropologists are wrong that the human species did not need the ability to cope with diverse natural environments.
We can actually represent this kind of information in a diagram. The anthropologists claim is that to survive, a specie needs to be able to survive in diverse environments. However, there’s an example of the specie, let’s just call them A.A. And these species, they did not survived, but yet they were able to cope with with diverse environments. The conclusion is that this claim is false.
Now, if we look at the question, we’re going to see it’s a bad argument. It’s definitely a bad argument because this example of the species not surviving yet having an ability to cope in diverse environments doesn’t reject this claim. Or this claim is saying is that for a species to survive, it needs to be able to cope with diverse environments. It doesn’t say that the ability to cope in diverse environments guarantee survival. It says that that ability to cope in diverse environments is necessary.
We use an arrow to diagram a relationship of sufficient and necessary conditions. The sufficient is always on the left because it leads to some other claim, to some other fact. Survival requires the ability to cope in diver environments. The necessary is always on the right. It’s something that’s needed for something else. So that’s why on the left, we have sufficient, on the right, we have necessary.
Now, this argument says that, or at least the example of the species that became extinct, they were able to cope in diverse environments yet they didn’t survived. Now, this example could weaken another claim. It could weaken a claim that says that diverse environments guarantee survival. Certainly, this example would weaken that claim because you’d have an example of a species that had this sufficient condition, this condition on the left, but did not survived. So this example definitely weakens this claim because coping in diverse environments wasn’t enough. It didn’t guarantee survival.
But this isn’t the claim that the anthropologists made. Remember, these are the anthropologists. This claim is actually a reversal of these two conditions. The anthropologists said that survival required an ability to cope. The example of the species weakens a claim that that ability to cope in diverse environments guarantee survival. So we’re going to say that the problem with this argument is that it reversed sufficient and necessary conditions. This might be happening a little bit too quickly but we’re going to spend the rest of the class today talking about sufficient and necessary conditions. So don’t worry if it’s a little hard to grasp right now. Let’s move on these answer choices, and then we’ll delve into a more deep discussion of this topic.
A, “Confuses a condition is being required for a given result to occur in one case with the conditions being sufficient for such a result to occur in a similar case.” Well, let’s take a look at this argument. The anthropologists were saying the condition of an ability to cope in diverse environments is required, is necessary. The example only challenges a claim that ability to cope in diverse environments are sufficient for survival. So answer choice A is correct, this argument confused sufficient and necessary conditions.
Answer choice B, “Takes for granted,” that’s another phrase for assumes, “that if one species had a characteristic that happen to enable it to survive certain conditions, at least one related extinct species must have had the same characteristic.” There’s nothing here about related species. The whole argument rests on the example of Australopithecus afarensis. So this answer choice doesn’t apply to the argument at hand.
Answer choice C, “Generalizes from the fact that one species with a certain characteristic survives certain conditions that all related species with the same characteristic must have survived exactly the same conditions.” Well, the species didn’t even survived. This Australopithecus afarensis. My pronunciation is getting better. So it didn’t survived. It doesn’t even tell us anything relevant to the argument at hand.
D, “Fails to consider the possibility that Australopithecus afarensis had one or more characteristics that lessened its chances of surviving prehistoric times.” Well, it actually acknowledges that an ability to cope in diverse environments wasn’t enough. So it doesn’t get into the specifics. So it didn’t really make this flaw, though. The flaw is that it reverse sufficient and necessary conditions. And once we’re good at recognizing this, we’ll be able to choose an answer choice like A and move on.
But, for the purposes of this lesson, we’re going to look at all the answer choices. So let’s go to E. “Fails to consider the possibility that even if a condition cause a result to occur in one case, it was not necessary to cause the result to occur in a similar case.” There’s no causal language in this argument. It’s not a cause-and-effect argument. It’s an argument about what is required for a species to survive. And the person writing this argument made the mistake that they thought that this requirement guarantees survival.
So that may have been a little overwhelming. As I said earlier, we’re going to spend the rest of the lesson today talking about sufficient and necessary conditions. So let’s take a look at some more general statements and get our heads around this material.