Data Sufficiency GMAT Questions are by far one of the toughest sections on the GMAT Exam. This video will show you tricks and strategies to do well on that section of the GMAT.
Data Sufficiency GMAT Strategies [Video Transcript]
Let me go ahead and fix that where it says, “June 16” because it is not June 16. It is July 14. Okay, ladies and gentlemen, July 14, 2011. Today’s topic is a continuation of what we were doing last time which was critical reasoning with blanks in the prompt. You remember last time, we only got to do a few problems because we got largely side-tracked into a side discussion about cause-and-effect arguments which was productive. It was a good digression. Definitely a digression of the positive variety, but a digression nevertheless it was.
So now we’re back, and we’re going to do a little bit more in the way of critical reasoning with blanks. But before we start that, as usual we have to start with the normal warnings and guidelines for participation here in the study hall. So let’s just go ahead and knock that out real quick.
The usual warnings, problem submissions, let me highlight a couple of these please, especially this one. I’m going to mention this a couple of times today, but I’m also going to plead with them to throw this up there on the actual Thursday’s website. Please do not submit OG problems. We can’t use them. In the past couple of weeks, there were a couple of submitters who appeared to have spent a great deal of time typing up OG problems and submitting them. We can’t use OG problems on the study hall. In fact, we’re not allowed to use anything at the study hall that we can’t also use on our forum.
So if you want to know where the list of banned sources is, check out the forums. On top of each of the general Quant and general Verbal folders, you’ll find a list of sources that we’re not allowed to use on the forums, and the same sources we are not allowed to use in the study hall. So make sure you are aware. Awareness is power.
Other things, please don’t submit too specific problems. If you just submit something that is a single problem and ask about one or two of the answer choices, that’s not really the kind of thing that should be on the study hall. That’s the kind of thing that belongs on the forums. In fact, individual problems like that are the entire reason why our forums exist. So make sure that your question is at least general enough to be a study hall question. But also as we said below, make sure that you do not violate the submission guidelines when you do that.
Also, please don’t submit personal issues. We had another couple of people over the last couple of weeks submitting things that are like, “Hi, I have a month left for my GMAT. How much should I study?” or, “How many hours should I study,” and things like that. Again, guys, this is a study hall that is watched by hundreds and hundreds of people, so not the place for personal questions and personal issues. We do have a place for that in our forums. That place is in the general questions folder on the forum. So please post those things there.
And if your question is specifically related to admissions, we also have the folder on the forum that is dedicated to admissions, consultant questions. One of our partner firms, mbaMission which is an admissions consulting firm mans that particular folder, and they’d be glad to take those questions.
So smiley face if you guys understand these guidelines. And hopefully if you’re watching this later as a recording, hopefully, you’re not fast-forwarding through these guidelines because we’d hate for you to waste your time with submissions.
Just some extra emphasis on a couple of these, these are already on the previous page, but people seem not to really grasp this yet, so here’s some extra emphasis. First, please, please, please do not submit problems from the official guide. We can’t use them. If you submit official guide problems, you are just wasting your time because we will have to reject them.
On the forum, we do talk about this, but GMAT has actually come to us and officially requested that we not use their official problems from OG. GMAT Prep, we are allowed to use because GMAT Prep is freely distributed software, so that’s a totally different story. But we are not allowed to use problems from the official guide, so please don’t use them.
The other thing, again, please don’t submit single questions. This week, I think as many as a majority of the problems submitted were just random single questions. Remember, that’s not the purpose of the study hall. It’s not what the study hall is here for. The study hall is here to address questions with somewhat of a more general theme. So if you just have a single question about a single problem, then please submit that on the forum.
Someone writes in the textbox, “These recordings are sometimes not very good. It cuts off the words.” I’m not sure what the issue is there, whoever’s writing that. You can always mention them to our tech support people. If you want to get in touch with them, there’s an email address. So if you’re having trouble with the recordings, then they might be able to help you out, tech support.
Again, smiley face if you guys understand these two principles especially. No official guide. No single questions without a context.
Okay, finally, please check the archives. Over the last couple of weeks, a number of people have been submitting requests for topics that are already contained in previous issues of the study hall. For instance, one gentleman submitted a request for probability, but we actually just finished doing a large-scale treatment of probability only a couple of months ago. I figure sometime in January or February, we had an entire study hall dedicated to probability.
Another person asked for data sufficiency on coordinate geometry, and that’s actually been the topic of not one but two complete study halls already. So guys, please check out the previous archives for topics before you post. We’ve already done about 40 of these study halls. So a lot of the stuff we’ve done has already been covered. To find these archives if you don’t know where these are located, you just go to the regular Thursdays with Ron page and you scroll down to below the submissions area where there’s a list of the archive sessions.
Questions before we get started? Smiley face if you’re ready to go. If you have any questions, please type them in the text box. All right, so let’s go ahead and check it out. This is the first problem of the day. When we view these problems as usual, what I’m going to do is give you multiple choice options. I’m also going to make sure that you can’t see each other’s answers.
So what you should have just seen appear near the left-hand part of your screen is this. So when we do these problems, please use these buttons. You should see multiple-choice polling buttons. In other words, these guys, these A through E choices right here. Smiley face if you see where these are located on your screen.
Okay, just to make sure we all know where these are, please pick “A” on your polling buttons so that I can make sure that all of you are the same page here. Everybody pick “A” just to make sure you can find these polling buttons. Okay, most of you have it. Please only click once because if you click twice or if you click any number an even number of times, you’ll erase your answer. Okay, there’s still a couple of you, Cyrus [SP], you haven’t picked “A.” Madu [SP], you haven’t picked “A.” Muka [SP], Robby [SP], SSS, you guys. Okay, most of you have this.
All right, let’s go ahead and move on to the first question of the day here. Again, please use the polling buttons to answer the problems. Here’s the first question. Okay, everybody, make sure you pick something. That’s about two minutes. One or two of you have not. Okay, there we go.
So here are the class results. So we are definitely all over the place on this one. Let’s start from the very first principles. We haven’t talked about what question type this is because problems with blanks, we did mention this in the last study hall, but problems with blanks are not a separate type of question. So when you see a blank, what you’re looking at is a problem that fits into one of the other categories.
So the problem at hand should fit into one of the other principal categories of problems. And your job is to figure out which one that is. So it should be either find the assumption, draw the conclusion, strengthen-weaken or explain the situation or discrepancy. A fifth type these problems is bold-faced problems, but you can’t hide a bold-faced problem with a blank. It wouldn’t really be possible to do that.
So which one of these is this problem? Go ahead and say it in the textbox. Is this find the assumption, strength and weaken, draw the conclusion or explain the situation or discrepancy? Yeah, a few of you are answering and definitely comes closest to explain the situation. You could make somewhat of a case that it’s a weaken question if you create an argument that you can weaken, but it’s definitely not an assumption or a conclusion question.
Let’s look at what’s going on here. In order to figure out the question type, look at the overall landscape of the argument to see what’s going on. So what’s happening in this passage? Think main ideas first. Don’t think incredible nit-pickiness at first. Think main ideas, and think principally what is going on here.
So the main idea here is that the government started paying elderly people more money in this country. So the government increased the amount paid to the elderly. And they all got it, and there hasn’t really been any inflation, but they’re not any better off than they were. So they received the payment, but they are no better off.
This is not an argument. So that’s the reason why it’s an explain the discrepancy problem. Make sure you know the difference between these types too in terms of which ones are actually arguments and which ones are not arguments.
This is an argument. The passage needs to be an argument. And if you’re going to strengthen or weaken something, the passage also has to be an argument. On the other hand, when you draw the conclusion, the passage is not an argument because your job is to actually come up with the conclusion. Remember an argument is something that has a conclusion in the first place. And then when you explain the situation, it’s also not an argument. It just presents you with a weird group of facts, and your job is to figure out those facts.
So this is not an argument, and it has a surprising result in it. So that means that what we’re looking at here is an explain the discrepancy problem, at least that’s the model that fits this problem most closely. So not an argument, a surprising result. So we need to explain the discrepancy.
Inferences may explain the same thing as a conclusion as far as these things are concerned in response to the question in the textbox. Okay, so this is an explain the discrepancy problem. So now that we’ve figured that out, let’s take a look at it. So this is an explain the discrepancy.
If you want a more in-depth treatment of explaining the discrepancy, then you can go to the whole study hall on that topic. That’s on February 3rd, so let me just go ahead and type that on the board. If you want more detail on these problem types, check out the February 3rd of this year.
Basically, the deal here is that when you have an explain the situation problem, you have to figure out what has happened that is not normal, and then you have to figure out something that will explain it. So what is not normal or what violates our usual expectations and then bring in something from outside the scope of the argument that could reasonably explain.
So let’s answer this question. In this argument, what is not normal? What violates our usual expectations in this situation? Textbox, please. Yeah, and that captures this pretty nicely. These people were actually given more money, but somehow they’re not any better off even though they’ve actually been given more money. So what we need is some means by which their standard of living is being kept from going up.
So right, a 20% increase and I think ID or LD says, a 20% increase should normally improve their financial situation. So despite receiving more government money, these people are not any better off. So what we need is we need a factor that can equalize their standard of living with the previous value even though they are being given more money by the government.
Remember, scope is not a concern here. In fact, these problems are supposed to pick something that’s out of scope. Remember, here’s your answers from last time, all over the place. So what I’m going to do now that we have this extra discussion here, I’m going to go ahead and blank your answers, and let’s vote again because there was no consensus really at all last time. So previous answerers, please re-vote now that we have a little bit of extra insight.
Let’s see what’s going on here. Okay, about half of you still haven’t picked a new answer. Okay, I’ll give you about 10 more seconds. Let’s see. Definitely still not a lot of agreement here. Okay, you guys have all answered except me, I need to answer.
Okay, here’s what we have. Interestingly, the class performance shifted but is basically around the same level it was previously. Correct answer to this is E. Let’s talk about why. Remember what you need. You need something that can work against the 20% increase that these guys are getting from the government.
So what E says is that the children only give their parents enough money to reach up to the threshold of a comfortable living. So the reason that would explain this situation is that if the government gives them more money, then the children are just going to give them less because basically, the children are just giving them enough to make it to this exact standard of living. And so it doesn’t matter how much help comes from them and how much comes from the government. According to E, if the government gives more help, the children will just give less help.
So someone in the textbox is saying, “Isn’t that out of scope?” Yes, it is out of scope, and that’s actually the whole point because remember, when you do explain a discrepancy problem, you have to have something that is out of scope because for any explain the discrepancy problem, your answer will always, always be outside of the scope of the original passage because the original passage has a discrepancy. That means in the original passage, we don’t really fully understand the situation. So in order to understand the situation, you have to bring in extra facts. So out of scope is not only not an issue here, it’s actually essential.
So we’ll take a look. Let’s take a look at the other choices. The other choices, you need to very carefully read what’s going on in the passage here. So before we look at the other choices, does everybody see how E works? Smiley face if you understand the way this works. Yeah, it’s basically, they cancel each other out is one way of thinking about it because it says the children will just give them enough to get them up to X value.
So as an analogy, think about this. Imagine if parents are just going to pay whatever it takes to pay off a child’s tuition bill at college. Then if the child gets financial aid, then that’ll mean the child gets more money overall because whatever money they get from financial aid, the parents will just pay that much less. So it’s still the same total sum as what’s going on in E. It’s like getting financial aid from the government so that children don’t have to pay as much.
Okay, so we’re good on E. Let’s explain away the other choices here. So let me pull some of these things from the previous slide. Okay, so what we need here is this. We need something from outside the scope. That could reasonably explain, and then we also need to…okay.
So let’s take a look at the wrong answers. All right, we’ll address that thing in the textbox in a second. They rely entirely on the government pension for their income. This would definitely not explain the situation. In fact, if this is true, then the situation becomes impossible to explain because if A is true, then that means these people are definitely receiving 20% more income no matter what. So if that’s a fact, then it’s actually impossible to explain the situation.
B doesn’t matter because the passage says that they got the money. B would be an issue if it actually prevented these people from receiving the money that they were given. But the increase has been duly received by everybody who is eligible for it, so there. We don’t care how long it takes to get to them as long as they eventually get it. If B said that the banks were so corrupt that half these people didn’t get their checks, that would be another story.
C talks about what happens in times of inflation, but you’ve got to read the passage. This is irrelevant because that discusses what happens during inflation, and the passage actually guarantees us that there is no inflation or negligible inflation. So inflation of the intervening period has been negligible, so this consideration knocks out answer choice C because C is only a factor if there is actually inflation which the passage says there is not.
And then D says the pension was increased when the number of Runagians below the poverty level reached an all-time high. D is a motivation behind the action, but it has nothing to do with the consequences of the action. In other words, D is just saying here’s why they were motivated to do this, but in other words, it tells us nothing about what will actually result.
Okay, some questions that are in the textbox here. There’s a lot. Let’s see. E forces us to assume the children…okay, so here, let’s take a couple of these questions. There’s this. Okay, this one. E forces us to assume the children know how much the parents are receiving from the government.
It does, but the answer choices are facts. So the answer choices are assumed to be true. Yeah, the answer choices in these things and in any explain the discrepancy problem, you’re assuming the answer choices are the truth. So this includes all assumptions that are necessary for these statements to be true. So if it says children supplement them only by enough to provide them with X, then yes, they do have to know how much is required to do that. And so we can safely assume that they do know that.
Okay, let’s see what else. This one, this poster says, “If the children always supplement the income, then why is the government concerned?” This is not the way that you attack these problems. We’re not the motives of things that are facts. So you can’t question facts.
Okay, what you’re saying here is it’s not productive for the government to pay extra money if E is true. You may be correct, but this doesn’t matter because the fact is that the government is paying extra money. So it doesn’t really matter how ill-informed this policy is because it’s policy. So your job is just to say, “Okay, the policy is what it is, and it’s having this effect. Let’s figure out why.”
Okay, what else? Muka [SP], I don’t really know what you’re typing there with the splits. I don’t know what B/W means or I’m not really sure what’s going on with the math there. B divided by W or whatever you’re typing.
Let’s see, okay, the last question we’ll address before we move onto another one. There’s a question here from Carlos which says the following, “If the 20% increase was evenly split among all elderly, which you explain, would you agree that it explains why they are not perceiving an increment?” This is not the right idea because it doesn’t matter where they start from. It just says that they’re no better off financially.
An increment is an increment. In other words, if you receive more money starting from point X, then you are better off regardless of where point X is. In other words, if these people are very poor to start with, it’s still an increment. They’re still better off. If they’re very rich to start with, it’s still an increment.
So the starting value is irrelevant because we’re not concerned with where they end up. We’re just concerned with where there is a difference. So we are not concerned with where they end up on the income scale. We are only concerned with whether there is a difference, and D doesn’t affect whether there’s a difference.
Okay, yeah, these things, you usually don’t have to think about hard numbers with these problems unless the problem itself actually contains hard numbers. In most other cases, that’s usually just going to complicate the issue. But I think we’re good on this one. I think we’re ready to move on.
The default interpretation of this statement is that it’s a 20% increase to everybody. It might be that there’s some kind of language barrier or something, but this is the…it says increase of 20%, increase in the amount paid to all of them means what it literally says. It means that all of them experience the increase. So that’s the default interpretation of something like that. If you interpret that as a 20% increase in just the total sum, then they will absolutely have to say that explicitly. You would have to say the total sum of payments was increased by 20% which doesn’t say here. So the splitting is not uneven.
Okay, let’s move on to something else. Let’s look at this. Okay, again, please use the polling buttons to answer the question. Okay, there’s a timer. Okay, let’s see. Robby Singh [SP], we’re still waiting for you and Mary Smith. If you have to guess, go ahead and make a guess.
Okay, here’s what we have so far. So it looks like it’s a toss-up between B and E this time, but what type of question is this again? Textbox, please. So another explain the situation question, yeah. So because the situation is or discrepancy, yeah, same thing. So the situation here is the passage is not an argument. It’s just a description. It just describes what is going on.
Here’s what’s going on. You have, “Drugs have been found,” medicinal substances is just a way of saying drugs, “have been found in lakes and rivers. However,” and this is an important fact, “the drugs are present in quantities too small to affect humans in any way.” Very important, too low to cause any physiological response, so pointing this out hopefully is going to make a couple of you reconsider your answers. But this means that they cannot do anything to people directly, nothing good and nothing bad, nothing. So yet, experts say that they could still benefit humans.
So what we need here is we need to explain this. To explain the discrepancy, we need some sort of benefit that will accrue to humans without any direct effect of the drugs upon humans because the passage has already said that there are not enough drugs in the water to affect humans in either a good way or a bad way, just not in any way. So what we’re left with is we need to find something that will benefit humans without directly affecting them.
So that’s what E does. So all right, I’m removing them. Let me fix some text over here. Experts say that removing the drugs could still benefit humans, so some sort of benefit without any direct effect. So E does this because what’s going on in E. According to E, taking away the drugs will affect disease-causing bacteria by making them less resistant to the drugs. This will benefit humans.
Right, remember when the textbox statements seem like a trap, remember that these problems are not like that. You’re making the mistake of thinking this is a draw the conclusion question. This is an explain the discrepancy problem where you are supposed to take out-of-scope factors that could reasonably explain some situation within the parameters of an argument. So if that statement is true in general, then it will absolutely hold true for whatever happens to be in these waters.
But yeah, this is not a draw the conclusion question. This is not rigorous type thinking where they have to put the same boundaries on the answer choices that they do on the passage. That’s how conclusion questions work, but if you approach this kind of question with that kind of approach, you’re going to get in trouble. They’re looking for more abstract relationships here.
So notice how this works. The passage requires that whatever we’re talking about not be a direct effect on humans because the passage has already said that there’s not enough drug in the water to do that, but that works because the humans are not what’s affected here. The bacteria are. And then the bacteria in turn, would have an effect on humans.
The other popular answer was B. The problem with B is that this is still a…there’s actually two major problems here. The first problem is that this is still a direct physiological effect on humans, so it won’t happen. But more importantly, if B were true, then it actually totally works against the argument. So it works completely against the argument because it supports leaving the drugs in the water.
So it’s interesting that choice B was as popular as it was because it actually works against what the experts are saying. It’s saying that if you leave those things in there, then they will counteract other things which the experts are saying if you take them out. So if B is true, then what the experts are saying makes no sense at all. And remember that you’re supposed to be taking the side of the experts here.
But more importantly, none of these things are going to happen anyway because the passage guarantees us that the drugs in question are not present in enough of a concentration to make a difference.
Okay, any questions? You don’t need to use the hand button. You can just type your question in the textbox. I didn’t pick C…stayed there for a while. C has got nothing to do with the drugs in the water though. C is talking about people being treated with drugs that contain these substances. It’s irrelevant to the situation at hand here because remember that the water is not exposing these people to these drugs in sufficient quantities to make any difference. So there’s not going to be any interaction between the drugs from the water and the drugs that might be prescribed because the drugs in the water are not present in enough of a concentration.
Someone in the textbox is saying, “I cannot hear you anymore.” You may want to try audio setup if you can’t hear. The question why B is against because counteracts…I don’t know what you mean by counteract, arrow, arrow, no harmless, but if you look at choice B, choice B is saying the drugs in the river are good for you. So basically, that would work against taking them out. Counteract…
Most people thought that counteract implied that they would work with the drugs. In any case, the easiest way to get rid of B is to realize that the drugs in the river are not affecting people. So the reason we have listed as number one here. So you know that none of this matters because the drugs that are in the river are not affecting people, and B is only a factor if the drugs in the river do affect people, so…
Someone says, “Isn’t discrepancy either strengthen or weaken?” Absolutely not, they’re very different question types. Strengthen or weaken, you actually have an argument and you’re trying to either support the argument and give it a little more strength or you are trying to oppose the argument or defeat it. These are not even arguments. These are just things that are happening that are weird that you have to try to explain.
Quick suggestion, if you’re asking a question like this, then…I’m going to highlight this on the board. I don’t mean to make an example of any particular person, but I’m just trying to give you some guidelines here. A question like this indicates that you probably aren’t ready to do GMAT critical reasoning problems yet because this kind of question means that you don’t really know what you’re doing.
And so if you go through a question and you’re not even really sure what you’re supposed to do, you’re just wasting the question. And as you know, the number of materials out there that are good is pretty small. Aside from official materials, most of what else is out there is pretty bad. So these things are treasure. You don’t want to waste them.
So instead, if you have trouble with this sort of first principles, then here’s what you should do. If you have trouble with first principles, in other words, how basic question types work etc., then do not do the real problems yet until you can create your own. So that’s my suggestion here. Make sure that you can create your own easy problems of each question type before you move onto real ones. If you can’t, then you don’t understand the basic format of questions enough to proceed.
So here’s an example. I’ll also make up a couple to show you what I’m talking about. In a sample explain the discrepancy, passage could be something like, “My friend is eating more food than ever before. However, he is losing weight.” Explain the discrepancy. Can anybody give me a correct answer to this? There’s like 10 million possible correct answers, but can anybody give me something that would explain?
“He’s working out more.” That works. Yeah, running. So possible correct answers could be something like he is exercising more. He is taking drugs that is causing him to lose weight. Yeah, sick with some sort of wasting disease, say a tapeworm would be a wasting disease. He’s eating higher quality food or low calorie food. So you get the point.
If you do this with very easy questions like this, you’ll start noticing the answers to your own questions. It’s definitely not going both ways. If I say something like he’s exercising less, that absolutely does not work to explain the discrepancy. In fact, it just creates even more of a discrepancy. Same thing, the opposite of any of these statements would not be helpful. And that’s how you would make a sample of explain the discrepancy, that kind of thing.
So if you’re having trouble with these first principles, make sure that you can create your own problems before you start moving on to GMAT problems because this is what we see with way too many students is that they just don’t understand what is happening before they start diving into all these hard problems. And I think a big part of the problem is this obsession that people have with “high-level problems.” We get a lot of people who are looking for what they call 700 plus problems who don’t even know how the problems work. But they’re so obsessed with numbers and stuff that they’re still worried about 700 plus. So you have to make sure that you understand the basics before.
Okay, someone is saying, “Stop tracing drugs.” No, trace amounts mean small amounts. A trace amount means a very tiny quantity or something. So this is not a verb. Trace is not a verb here. This is like small quantities. So there are small quantities in the water. The experts are saying that you should take those small quantities out. All right, I hope that helps. Let’s move on. Yeah, trace amounts are small quantities.
Let’s take a look at something new. Try this. Go for it. Remember to use the buttons, please. And here’s a timer. I’ll give you a little bit extra to answer. There’s a couple of you who don’t have answers, so I’ll give you an extra 10 or 15 seconds.
Okay, let’s take a look. This was actually quite good for the most part. Let’s see what we’ve got here. Here are your responses. Does anybody know what type of question this is? There’s actually two ways you can answer this, so don’t be shy. You can think of it as explain the situation. Yeah, fill in the blank, ha ha, hee hee. Or you can think of it as a weaken question. It depends on how you do this.
Let me show what I mean. There is a certain amount of overlap. There will never be overlap between draw the conclusion, find the assumption and other question types because those are different animals. But strengthen and weaken and explain the discrepancy are both bringing in things from outside the scope, so you can have some overlap between these.
You can think about this one as a weaken where the argument is people. The items that a sample of people bought at FoodBasket were more expensive at ShopperKing, therefore random shoppers at ShopperKing would save money by switching to FoodBasket. And you’re trying to weaken this because what it says is that it does not necessarily show, so you can think of it as a weakener of it does show this.
Or you can think about it as an explain the discrepancy situation. Just think of it as a non-argument, as a collection of facts. The items that a sample of people bought at FoodBasket were more expensive at ShopperKing. However, random shoppers at ShopperKing do not pay less on average than they do at FoodBasket. So if you think of it as a collection of facts, then now you have to explain this discrepancy.
Both of these basically work out the same. There’s really not much of a difference as one might think because notice that these are both question types in which you have to bring in outside information. So according to either of these interpretations, you need something that’s out of scope, and it needs to show that the savings experienced by the sample shoppers does not translate into a general savings relative to the other store.
So in this case, people are saying it’s weaken. People are saying it’s explain the discrepancy. You guys are basically both right. But in either of these cases, the ultimate interpretation should be that we’re looking for this kind of thing. Smiley face if you understand this.
Okay, so we need something that is outside the scope, and it needs to show that these savings experienced by the sample shoppers does not translate into a general savings relative to the ShopperKing store. So translated into other words, what this means, this means that we need a reason why these shoppers would save money at FoodBasket but why other shoppers wouldn’t. So something has to be special about these shoppers because there has to be some reason why this particular population of shoppers saves money at FoodBasket even though random shoppers wouldn’t.
And that’s what A does because A says that they don’t offer low prices across the board necessarily that they would just offer low prices on certain items. So choice A gives reason to believe that the sample is not a random sample. According to A, our sample is likely to consist of people who come to FoodBasket because the items that they want to buy are cheaper at FoodBasket.
It’s like if any of you guys have Trader Joe’s where you’re at, Trader Joe’s tends to have very low prices on things like meat and vegetables and insanely high prices on everything else. So if somebody walks out of Trader Joe’s with a basket full of meat and vegetables, then prices are going to be lower, but that doesn’t mean prices are going to be lower across the board. It’s like that.
So let’s take a look. You didn’t know, what? About Trader Joe’s? Yeah. Trader Joe’s prices on these things are pretty good at least they are around here where I live.
Okay, other popular choices. I don’t think any of you picked anything except A, B and C. So for B, B actually works the wrong way because B is even more. In other words, ShopperKing is even more expensive for these people. So choice B is definitely working in the wrong direction because choice B is more evident that ShopperKing is more expensive in general. So we want evidence that ShopperKing is not more expensive in general, and that it’s just a special case for these people coming out of the store.
Many shoppers consider factors other than price in choosing a supermarket at which they shop most regularly. Okay, but this doesn’t really explain what we need. If C is true, it doesn’t help us at all with what we need which is this. In other words, we need a reason why those people coming out of the store would not be paying the average price at the store. C is interesting, but C doesn’t really contribute either way to this issue. It doesn’t help us resolve this either way.
You’re bringing in a relative concern. Because if you say something like, “My friends who are married to white women, their wives are taller on average than my friends who are married to Asian women. Therefore, all white women must be taller than all Asian women,” where you would need to bring in something, another kind of selection according to height to prove that that wasn’t true. C is like saying people are choosing their wives based on things other than height which is great, but it doesn’t really explain away the difference in height that actually exists. It just doesn’t do anything.
Other questions about this problem? If you have them, then please put them in the textbox. If not, we’ll move on. Okay, let’s move onto another one. Let’s try…
“I think it is not necessary to…” It’s not an issue of wasting time because some people might come up with one of those classifications first, and some of them might come up with the other one. What I’m not saying in case you’re interpreting it this way is I’m not saying you should interpret this in both of these ways. I’m just saying if some people thought of one interpretation and some thought of the other one, then they’re both right. So no, no, you don’t have to come up with both. Absolutely not. If you come up with one workable frame in which to think about a problem, then that’s all you need. But there’s no superiority of either one. They’re both valid ways to think of a problem.
Okay, let’s take a look…yeah, it just depends on how you think about them. They’re the same type of deal. Let’s take a look at this one. You know the drill. Please use the answer buttons. Go to town. Okay, there’s still a few of you with no answers, so I’ll give you an extra 15 seconds or so. Okay, I think we have answers from everybody.
So let’s take a look. The deal here, this is another one of those problems where it’s basically either a weaken or explain discrepancy depending on how you want to personally think about it. So let’s view it in those two ways.
You can think of it as a weaken. If you think of it that way, then you have to come up with an argument that you’re actually trying to weaken. The argument would be, “In the past, this rate of business loss has been overcome. Therefore, the business district will rebound again.” And you’re trying to weaken this particular conclusion because you’re saying confidence that it will rebound again is ill-founded. So you can think of it that way or you can think about it as explain the situation.
In this case, it’s just a collection of facts. In the past, this rate of business loss has been tolerated-overcome. However this time, it is unlikely to be overcome. So you need to explain this. So in either one of these cases because there’s two different ways of thinking about it, but in both of them, we need some out of scope reason. According to either of these interpretations, we need an out of scope new reason why this situation is fundamentally different from previous catalogs. In other words, we need a reason why the situation is different from previous times, why are we not likely to rebound again. So we need some new reason, out of scope reason why this downturn is going to be more difficult to overcome.
So A, stores likely to be put out of business are anchor stores on whose buildings that draw shoppers many of the other stores depend. So the stores likely to be put out of business are stores that the other stores depend on. So according to A, this indicates that the business loss will be more severe than in previous years because not only are these stores themselves are going out of business, but their closure will also reduce other stores’ business. So it’s not just another instance of a bunch of stores closing. This time, you have a bunch of stores closing in ways that we are told are going to affect other stores. So choice A takes care of this.
Let’s take a look at the other choices and see why they are not correct. Smiley face if you guys understand why A works here. Not a lot of smiley faces.
Okay, let’s take a look at the other answer choices. If you look at B, a couple of you picked B. Remember we need a reason why this business downturn is worse than previous ones. B says the bus line that has long connected the downtown areas, tradition of carrying shoppers into downtown Morganville to shop.
So this just says there’s a bus line, but there’s no indication that these people won’t continue to use it. So if choice B had said, “Because SaveMart is there, people will no longer use this bus line,” then you’ve got something. Then they would stop coming into downtown, but it doesn’t say that. It just says that there is a bus line that has historically done this.
C, when the downtown shopping district has rebounded before, businesses were typically taken over by a business of the same kind. This just describes what happened before. There’s no discussion of the present downturn at all, and hence, no rationale for why it might be more serious. C is just a historical discussion of what has happened in the past, but C has no indications though that this might not happen again.
So SaveMart…[inaudible 1:15:45] see textbox. So yeah, SaveMart sells the same kinds of stuff as the stores that went out of business, thereby no new motivation for new businesses to open up. Well, where are you getting the idea that there’s no new motivation for businesses to open up? You’re assuming that these places won’t be filled by discount stores instead, they’ll compete with SaveMart.[inaudible 1:16:24] Yeah, but see that’s the problem. This choice doesn’t say anything about what will happen this time. Remember that one of the most common incorrect answers that you’ll see in critical reasoning, one of the most common incorrect patterns you’ll see in critical reasoning is a description of past behavior that is trying to trick you into assuming that the past behavior will continue. And it doesn’t say that.
You can’t just assume that past patterns will continue. So this is a very, very common wrong answer pattern is when they just say that X has happened in the past. And then if you assume that X will just happen again, then you get trapped because that’s not an assumption that you’re allowed to make.
So, doesn’t even A assume certain things? It assumes things that are trivial. The only things assumed by A are things like if the stores that shoppers depend on or if the stores that other stores depend on go out of business, then those other stores will suffer. That’s a pretty common sense assumption.
Remember that you can make common sense assumptions. You cannot make non-common sense assumptions. Assuming that everything that’s happened in the past will continue in the present is not a common sense assumption, so you can’t make that. SSS says that, “What does that mean?” It means that the other stores need the anchor stores in order to bring people in. So in other words, if the anchor stores close, then these other stores won’t get as many shoppers. So it’s not directly affording the loss, but the issue is it’s the fact that they won’t get the people that were previously drawn in by those anchor stores.
Rusty says, “Isn’t part of A as representing past behavior?” It’s not. If you notice the way that A is phrased, it talks about how things are right now. Notice that all of this is present tense, so this is not indicated as a past pattern at all. This is indicated as the way that things are right now at the present moment or in general. It’s what the present tense signifies.
Well, again, PWI, you can’t assume random things. That’s an assumption that has no support. It’s basically just made up at random. There’s no reason to believe that and not to believe that the opposite won’t happen. So you would need to be given that. You can’t just assume that that will happen.
As an analogy, let’s say that someone’s making $100,000 a year and loses their job, and then the argument says they will probably have less income, what you’re saying is like saying you can just assume that they will find another $100,000 job which is not a safe assumption. That’s definitely, definitely stretching it.
So you really have to make sure that your assumptions are total common sense when you make them. So in these problems, there’s no rules-based way to figure this out. You just have to understand with intuition, but when you make assumptions in these problems, make sure that they are completely common sense assumptions, in other words, assumptions that are so clear that they would be very weird if they were not true.
Okay, we’ve got to…these businesses are not being replaced by SaveMart. That’s an incorrect reading of the passage. Notice that SaveMart came into the neighborhood and then the businesses closed. So that’s an incorrect reading of the passage. In fact, they haven’t even gone out of business yet, so 20% of them will fail because SaveMart opened in another city.
So Neil [SP], you’ve got to read the passage more carefully because you read it as SaveMart replaced the stores that closed, totally not what happened. What happened is SaveMart opened in another town, and then in the future, some stores will close as a result later.
Okay, we got to wrap up here. We are about five minutes over. If you have administrative questions, I’ll take those super, super quick. Otherwise, have a wonderful two weeks. Yeah, “Feel better.” I don’t know if I can feel that much worse. I’m not feeling so hot here.
We don’t post the slides, but we do post the recordings. So the recordings are at the Thursdays with Ron site. So yeah, it’s the recordings because the slides generally wouldn’t make a lot of sense without the recording especially when it comes to math on both parts.
You should read the question stem first because the questions stem tells you what you’re doing. If you don’t read the question stem first, it’s very difficult to be oriented, so yeah. Okay, this is not the time for extraneous questions. We have to go. I have to run. I have some appointments to go to, but if you have any quick administrative questions, I can take that.
These questions were from GMATPrep, so… SSS, I don’t post recordings. That’s our tech people do all that. I don’t do any of that. Okay, all right. Thanks, guys. Going to log you guys out here in about 30 seconds. Yeah, man. I still live down there in Florida, I wouldn’t mind coming back. All right, good night. Good luck. I’m going to log you guys out in about 30 seconds. Have a good two weeks.