Detective: Laser-printer drums are easily damaged, and any nick in a drum will produce a blemish of similar dimensions on each page produced by that printer. So in matching a blemish on a page with a nick on a drum, we can reliably trace a suspicious laser-printed document to the precise printer on which it was produced.

Summarize Argument
The detective concludes that he can connect a document to the laser-printer from which it was printed by matching a flaw on the document to the printer’s drum. This is because a flawed printer drum produces a similar flaw on the paper it prints.

Notable Assumptions
The detective assumes that the flaws on the drums are unique and, in extension, that several drums don’t have the same flaw. He also assumes that he can access the flawed drums to compare them with the flawed documents.

A
Criminals are unlikely to use their own laser printers to produce suspicious documents.
This does not affect the argument. The detective doesn’t claim this method will lead him to the criminal—the detective only claims that the method will lead him to the precise printer from which the blemished document was produced.
B
Drum nicks are usually so small that it requires skill to accurately determine their size and shape.
This does not affect the argument. The skill required to accurately identify drum nicks is not up for question; the usefulness of the method outlined by the detective is.
C
The manufacturing process often produces the same nick on several drums.
This weakens the argument. If several drums have the same nick, the detective would not be able to reliably determine which printer produced the blemished document using his method.
D
Blemishes on documents are sometimes totally concealed by characters that are printed over them.
This does not affect the argument. The detective only argues that a document can be traced when a blemish on a page can be matched with a nick on a drum—if the blemish can‘t be identified in the first place (and thus can’t be connected to a drum), the argument doesn’t apply.
E
Most suspicious documents are not produced on laser printers.
This does not affect the argument. The detective is only concerned with documents printed from laser-printers.

7 comments

The question stem reads: The Conclusion follows logically if which one of the following is assumed? This is a Sufficient Assumption question.

Love is complicated in the real world, which is no different than love in the LSAT. It's possible to love someone and not be loved back. Unfortunately, love is not a biconditional. My previous relationships confirm that. While reading this stimulus, it is essential to see which "way" the love is going. Are you loving or being loved? The stimulus is short and conditional heavy, so let's break these down as we go. The stimulus starts with "whoever is kind is loved by somebody or another." This translates into the lawgic:

kind -> loved by someone

Next, the stimulus claims that "whoever loves anyone is happy." This translated into the lawgic:

Love anyone -> happy

The argument concludes, "Whoever is kind is happy." Translated:

Kind -> happy

Let's organize this argument into:

P1: Kind -> loved by someone

P2: Love anyone -> happy

______________________________________________

C: Kind -> happy

We can kick up the sufficient condition so we now have:

P3: Kind

P1: Kind -> loved by someone

P2: Love anyone -> happy

______________________________________________

C: Happy

We want to get to "happy," and P2 will get us there if we can satisfy "love anyone." Let's make that our necessary condition: (__) -> love anyone. Now we need to find a sufficient condition that will be satisfied by the argument. Notice how P3 satisfies the sufficient condition of P1, so we can infer that "loved by someone" occurs. Let's make "loved by someone" the sufficient condition of conditional: loved by someone -> love anyone. Now we have a valid argument:

P3: Kind

P1: Kind -> loved by someone

SA: Loved by someone -> love anyone

P2: Love anyone -> happy

______________________________________________

C: Happy

P3 will trigger P1, P1 triggers our SA, and our SA will trigger P2, which brings us to the desired conclusion of "happy." Happy is exactly what we are because we just solved this four-star problem. Let's move to the answer choices.

Answer Choice (A) is incorrect. If you picked (A), you likely misread P1 and thought that being kind meant you loved someone. You can rule out (A) quickly by seeing we are missing the concept of "loved by."

Answer Choice (B) is also out. You can rule out (B) because we are missing the concept of "loved by."

Answer Choice (C) is also out. We want to get to "happy," but (C) has "happy" in sufficient condition; we can rule (C) out.

Correct Answer Choice (D) is the contrapositive of our prephase. (D) translate to:

Loves no one -> loved by no one

We take the contrapositive:

/(loved by no one) -> /(loves no one)

Not being loved by no one means you are loved by someone. Not loving no one means you love someone. So we get our SA: "Loved by someone -> love anyone."

Answer Choice (E) is the most popular wrong answer. If you picked (E), you likely thought that (E) would let you infer "loves everyone." "Loves everyone" would satisfy "loves anyone" and deliver you to "happy." The problem with (E) is that it has "Kind" in the necessary. Remember, satisfying the necessary condition has no effect on the sufficient condition.


16 comments

The question stem reads: The reasoning in the argument is most vulnerable to criticism on which one of the following grounds? This is a Flaw question.

The author begins by claiming that it is clear that Egyptians were the first society to produce alcoholic beverages. That sounds like a conclusion; let's see the author's evidence for that claim. The author then describes how it had been thought the Babylonians were first because they had a process for fermentation around 1500 BC. However, archaeologists have found an Egyptian cup from 2000 B.C. With chemical residue that indicates it contained an alcoholic form of beer. So the author's argument uses the premise that the Egyptian cup is the oldest evidence of alcohol to conclude that Egypt must have been the first society to produce alcohol. Immediately, we can see the author's line of reasoning as flawed. Let's go back in time to 5 seconds before the archaeologists found this Egyptian cup. Then, the oldest evidence we had of alcohol was from the Babylonians. Using the authors' line of reasoning, we conclude that the Babylonians were the first society to produce alcohol. We would be subsequently proven wrong when the archeologists find the Egyptian cup 5 seconds later. All that was needed to prove our argument wrong was finding new evidence that an older civilization had alcohol. Let's return to the present, where the author claims that Egyptians must have been the oldest society to produce alcohol. How do we know we won't find even earlier evidence of alcohol in the future? We can't. The author has made an error in assuming what is true of the past must be true in the future. This is the Problem of Induction.

However, there is an even more fundamental problem. What we humans know has no bearing on the actual truth of the matter. Even if we could see into the future and determine that this Egyptian cup would be the oldest evidence we find, we could not say that Egyptians were, in fact, the first society to produce alcohol. An earlier society could have created alcohol but left no evidence behind for us to find. The upshot is that a lack of evidence for a claim does not constitute evidence that the claim is false.

Answer Choice (A) is incorrect because the claim that Egypt was the first society to produce alcohol is not a generalization about Egyptian society. Either they were the first to produce alcohol, or they were not. A generalization would be that all Egyptians drank alcohol. If the author argued that all Egyptians drank alcohol because we found a single cup in a pharaoh's tomb, then (A) would look better.

Answer Choice (B) is wrong. The premises talk about two distinct types of alcoholic beverage (Egyptian beer vs. Babylonian wine). However, the conclusion talks about alcoholic beverages in general. Alcoholic beer counts as an alcoholic beverage.(B) would look better if the author used the old cup of Egyptian beer to conclude Egyptians were the first society to produce wine.

Answer Choice (C) is incorrect. If we mapped the stimulus onto (C), we would get the following: Because Egpyt developed fermentation before the Babylonians, the development of fermentation in Babylon depended on the development of fermentation in Egypt. Wildly off base from the argument, eliminate.

Correct Answer Choice (D) is what we prephased. The argument does ignore that the first known instance of alcohol (the Egyptian wine cup) is not the first instance of alcohol.

Answer Choice (E) is incorrect. While it is true that the author provides no evidence for the claim that they produced wine as early as 1500 BC, it is irrelevant. If it is true the Babylonians had wine as early as 1500 BC, the Egyptian cup is still older. If it is false, the Babylonians had wine as early as 1500 BC, and the Egyptian cup is still the oldest. Additionally, Even if the author provided evidence for the claim about Babylonian wine, we would still the argument would still be flawed due to the problem discussed in (D).


16 comments

Studies have shown that specialty sports foods contain exactly the same nutrients in the same quantities as do common foods from the grocery store. Moreover, sports foods cost from two to three times more than regular foods. So very few athletes would buy sports foods were it not for expensive advertising campaigns.

Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that the factor driving athletes’ purchases of sports foods is expensive advertising campaigns. This is based on the phenomenon that sports food are nutritionally the same as normal foods, but cost two to three times more. From the stimulus alone, we can’t tell how many athletes are currently buying sports foods; we only have the author’s conclusion that without the expensive advertising campaigns, that number would be very low.

Notable Assumptions
The author assumes that there are no factors other than expensive advertisements that could make sports foods more attractive to athletes than regular foods.

A
Sports foods are occasionally used by world-famous athletes.
This does not affect the argument. World-famous athletes could be occasionally using sports foods in private and consequently having no impact on how regular athletes perceive these foods.
B
Many grocery stores carry sports foods alongside traditional inventories.
This does not affect the argument. It merely reinforces the idea that athletes can choose between sports foods and regular foods at the grocery store.
C
Sports foods are easier than regular foods to carry and consume during training and competition.
This weakens the argument. It offers another explanation for why athletes are purchasing sports foods, outside of the advertising campaigns: convenience. The greater convenience of sports foods makes them more attractive than regular foods, despite the price difference.
D
Regular foods contain vitamins and minerals that are essential to developing strength and endurance.
This does not affect the argument. Sports foods and regular foods have identical nutrients in the same quantities.
E
Sports foods can nutritionally substitute for regular meals.
This does not affect the argument. Sports foods and regular foods have identical nutrients in the same quantities, so them being able to nutritionally substitute for regular meals is not new or useful information.

5 comments

Sambar deer are physically incapable of digesting meat. Yet sambar deer have been reported feeding on box turtles after killing them.

"Surprising" Phenomenon
Why do sambar deer feed on box turtles if sambar deer are incapable of digesting meat?

Objective
Any hypothesis that can resolve this will need to explain either that there is some reason for sambar deer to eat turtle meat without digesting it, or else that when the deer feed on box turtles, they don’t consume their meat.

A
Sambar deer eat only the bony shells of box turtles.
This explains that when sambar deer feed on box turtles, they don’t consume their meat. This reconciles the deers’ feeding habits with their inability to digest meat.
B
Sambar deer often kill box turtles by accident.
It doesn’t matter how sambar deer kill box turtles. We’re concerned about why sambar deer eat the turtles after killing them.
C
Sambar deer kill box turtles only occasionally.
It doesn’t matter how frequently sambar deer kill box turtles. We’re focused on why the deer eat box turtles after killing them.
D
Box turtles sometimes compete with sambar deer for food.
This may explain why sambar deer kill box turtles, but it doesn’t explain why sambar deer eat the turtles after killing them.
E
Box turtles are much slower and clumsier than are sambar deer.
This may explain why sambar deer can kill box turtles, but it doesn’t explain why sambar deer eat box turtles.

The question stem reads: Which one of the following, if true, best resolves the discrepancy above? This is a Resolve Reconcile Explain question.

In the Core Curriculum, we discussed how our job is to develop a hypothesis or explanation for the seemingly contradictory phenomena the stimulus provides. The stimulus tells us that "Sambar deer are physically incapable of digesting meat." Ok, the deer cannot consume and process meat for energy. But the stimulus also tells us that Sambar deer have been observed killing and feeding on box turtles. That’s puzzling. If the deer can’t eat meat, why are they killing and eating the box turtles? Our job is to explain that exact question.

Before we move into the answer choices, let's do some prephasing. We know that Sambar deer are incapable of digesting meat, so it would be bizarre if we noticed the deer consuming turtle meat. However, the stimulus says that the deer have been observed eating turtles. Is there more to a turtle than its meat? Of course there is! Perhaps the deer are eating the turtles' bones, skin, or eyes (are eyes meat? I digress). That would help explain the phenomena. The deer can’t digest meat, but they are not hunting and eating the turtles' meat; they are eating something else. Now that we have a solid prephase, we can join the Sambar deer and go hunting.

Correct Answer Choice (A) is exactly what we prephrased. (A) explains that the deer eat only the bony shell of the turtles. The deer are not killing and eating the turtles for meat (which the deer cannot digest); they are killing and eating the turtles for their shells.

Answer Choice (B) almost looks good but only provides a partial explanation. If you picked (B), you likely realized that (B) would explain why the deer kill the turtles when they cannot eat them. The deer aren't hunting the turtles. The deer are killing turtles by accident (turtle-slaughter?) However, (B) fails to explain why the deer go on to eat their unfortunate victims. Imagine your friend found you feeding on the carcass of a squirrel you had recently driven over and asked, "why are you doing that?" Responding through your blood-soaked teeth with, "I did it by accident," would leave your friend mildly horrified and still confused. For that reason, (B) is out.

Answer Choice (C) fails to explain both the eating and the killing. The fact that the deer kill and eat the turtles only on occasion does nothing to explain why they kill and eat the turtles when they cannot digest meat.

Answer Choice (D) is similar to (B) in providing only a partial explanation. (D) says that the turtles compete with the deer for food. That might explain why the deer have the incentive to kill the turtles. If they kill the turtles, the deer won't have to compete with them for food. However, that does not explain why they go on to eat the turtles. You could argue that the eating of the turtles is to strike fear into the other turtle's hearts and warn them away from the deer's territory. But at that point, though, we are making too many assumptions to make (D) work. So (D) is out.

Answer Choice (E) would explain how the deer are able to kill the turtles by saying that the deer are faster and more agile. However, our job isn’t to explain how the deer are killing the turtles, but why the deer are killing the turtles. For that reason, (E) is out.


7 comments

The question stem reads: which of the following most accurately describes a way in which Willet's reasoning is questionable? This is a Flaw question.

The stimulus begins with Benson's argument. Because we are interested in Willet's argument, we do not need to evaluate Benson's argument. However, it is still important to read Benson's argument to understand the context in which Willet's reply is made. Benson believes that maintaining the quality of life in his city requires that the city restrict growth. That is why he supports the new zoning regulations.

Willet replies that he heard the same argument (that protecting the quality of life requires restricting growth) ten years ago and five years ago. He then says both times; the city council was justified in not restricting growth. So he agrees with the city council's decision not to restrict growth. Willet claims that since there is nothing new in this idea of restricting growth, he opposes the new zoning regulations that restrict growth.

Right here, we have the fallacious reasoning that what is true of the past must be true of the future, which is an example of the Problem of Induction. The classic example is concluding that all swans must be white because you have only seen white swans. The conclusion is proven false once you eventually encounter a black swan. Similarly, Willet is assuming that because the city council was justified in not restricting growth in the past, it must be the case that there is no reason to restrict growth now. However, there may be new reasons the city should restrict growth that didn't exist five and ten years ago.

Answer Choice (A) is incorrect because Willet does not presume growth is necessarily good. We do not know his opinion on growth at all, only that the city council justified not restricting growth five and 10 years ago.

Answer Choice (B) is incorrect because there is no attack on Benson's personality.

Correct Answer Choice (C) is what we discussed. Benson assumed that what was true in the past must be true in the present/future. However, there might be new reasons to restrict growth now that did not exist five and ten years ago.

Answer Choice (D) is incorrect because other factors contributing to quality of life are irrelevant not only to Willet's argument but Benson's also to Benson's argument. Benso claims that restricting growth is necessary for maintaining the quality of life (maintain quality of life -> restrict growth). So it would not matter how many other factors contribute to maintaining quality of life; failing to restrict growth would result in an inability to maintain quality of life ( the contrapositive: /restrict growth -> /maintain quality of life).

Answer Choice (E) is arbitrary. If you picked this, you likely missed that Willet claimed: "The city council was justified in deciding not to restrict growth." It does not matter how qualified or poorly qualified they were; their decisions were justified. One can both be poorly qualified to make a decision and end up making a justified decision. One can also be both highly qualified to make a decision and also make an unjustified decision (looking at you, American politics).


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This is a Point at Issue Disagree question. We know this because of the question stem: Cox and Crockett disagree over whether…

Our job here is to evaluate Cox and Crockett's conversation and determine their disagreement. Notice how the question stem does not use the word "suggests" or "supports.” It simply says the word "disagree." That means the disagreement is explicit, which means our work got a lot easier. Cox and Talbot will state two claims that explicitly contradict each other. Once we find that, we can hone in on the correct answer choice.

Cox uses a bunch of referential phrasing in his statement. By now, you should be well-acquainted with referential phrasing, so I'll give you the translation:

"The consumer counsel did not provide sufficient (enough) justification for its action (the recall) when it required that Derma-35 be recalled from the market."

Did Cox even make an argument? No, all Cox has done is make a claim. He has provided no support for the claim the council didn't provide enough justification. Well, there isn't much to agree or disagree on. Either you think they provided sufficient evidence, or they did not. And Cox did not.

Crockett says he disagrees with Cox. Immediately, we have our answer. Crockett believes sufficient evidence was provided, and Cox does not. . Right here is where we can stop and start hunting for the Correct Answer Choice (D). But before we move on, let's evaluate what else Crocket has to say. He claims Derma 35 causes inflammation, but the council cited blemishes, which are a side effect of inflammation. Ok, so the council took this off the market because of blemishes. Crocket then claims that the council rightly acknowledged blemishes are a significant health concern. "Rightly" indicates Crocket agrees that blemishes are a health concern.

We know a lot about what Crocket thinks and little about what Cox thinks. In order to know if Cox and Crocket disagree on something, we need to know both of their positions on the matter. If we don't know at least one of their positions, we can rule out the AC. So as a matter of strategy, we will ask whether or not we know Cox's position on the answer choice. If we do not know his position, we will have no way of knowing whether he disagrees with Crockett.

Answer Choice (A) is incorrect since neither Cox nor Crocket state their opinion on whether Derma 35 should remain on the market. Since we don’t know anyone’s opinion on this matter, we can eliminate this answer choice.

Answer Choice (B) is wrong because we do not know where Cox lands on this. He might agree. He might disagree. We can rule this one out for the same reason we ruled out (A).

Answer Choice (C) is incorrect because Cox never mentions what justification the council gave. He simply says that it was not sufficient. We can rule this one out since we don’t know Cox’s opinion on this.

Correct Answer Choice (D) Cox explicitly says he agrees with this position, and Crocket says he disagrees. Correct Answer.

Answer Choice (E) is incorrect because we do not know if Cox believes this or not. Therefore, it is out.


4 comments

The question stem reads: Which one of the following logically follows from the literary historian's claims? This is a Must Be True question.

The stimulus begins with context by stating that Shakespeare could have written love poems attributed to him. We then turn to the author's argument with the indicator "but." The author claims that the dramas attributed to him "evince such insight into the minds of powerful rulers that they could only have been written by one who had spent much time among them." In other words, because the dramas provided such an accurate description of rulers' mental states, the dramas must have been written by someone who had actually been around to witness rulers themselves. The author has introduced "being around rulers" as a Necessary Condition for being the author of the plays. She then says that Francis Bacon spent time with rulers, but Shakespeare had not. Can we draw a valid inference? We can! Shakespeare didn't spend time with rulers, which means he could not have written the plays. Why? Because spending time with rulers is required for being the dramas' author. But if Shakespeare didn't write the plays, who did? The author says Mr. Bacon spent time around rulers, which means he satisfies the Necessary Conditions for being the author. However, by now, you know that Necessary does not mean Sufficient. So while Mr. Bacon may be the author, we don't know for sure. There might be other Necessary Conditions we need to meet to become an author of the dramas that Bacon fails to satisfy.

In an MBT Question, we hunt for any valid inferences we draw in the answer choices. We synthesized the author's claims and drew the valid inference that Shakespeare did not write the dramas and Francis Bacon possibly wrote the dramas.

We can find the inference that Shakespeare did not write the dramas in Correct Answer Choice (E), which also restates the context that Shakespeare could have written love poetry.

Answer Choice (A) makes a mistake by claiming that Bacon wrote the dramas attributed to Shakespeare. That could be true, but we do not know if he actually did. Additionally, (A) claims that Bacon did not write the love poetry attributed to Shakespeare. Why not? We have no rules or conditions about the author of love poetry, only that Shakespeare could have been the author. So Bacon is still in the running for that.

Answer Choice (B) makes the same mistake as (A) by claiming that Bacon wrote the Dramas. So for that reason, it is out. Additionally, we know nothing about the author of the love poems, so we can rule out (B) for the claim that Bacon wrote love poetry.

Answer Choice (C) makes the valid inference that Shakespeare did not write the dramas but makes the invalid inference that he did not write the poems. The author directly states that Shakespeare could have written the poems in the context so (C) is out.

Answer Choice (D) claims that one person could not have written both the love poems and the dramas. If we knew Shakespeare wrote the poems, then (D) would be a valid inference. However, we do not know that Shakespeare wrote the poems, only that he could have wrote the poems. So there is still the possibility that someone besides Shakespeare wrote love poems and dramas.


11 comments