Executive Pay

Tom: Executives in this country make around 85x what the average worker earns. This is an extraordinarily large disparity, and therefore public resentment over the size of executive's salaries is justified.

Martha: Such resentment is not justified, since wealth is created by taking risks and making decisions, actions most people prefer to avoid. Generous rewards for those who choose not to avoid these actions are both fair and necessary.

Tom: I think you misunderstood me. I'm not saying that people resent that there is a large disparity here between executives' salaries and workers' salaries, but rather they resent that it is atypically large: in other countries executives earn only 20 or 30 times what the average worker earns.

Which one of the following most accurately expresses the main point at issue between Tom and Martha?

Answer: whether public resentment of the size of executive salaries is justified (Tom says yes, Martha says no).

Difficulty Level: 1

Tom responds to Martha's critique in which one of the following ways?

Answer: He undermines the relevance of Martha's objection by making explicit his grounds for judging that the disparity at issue is unjustifiably large.

Difficulty Level: 3

Productivity at Work

Manager: One reason productivity in our office is not as high as it could be is that office workers spend too much time taking unauthorized breaks. Since the number of office workers assigned to each manager will soon be reduced, managers will be able to supervise workers more closely in the future to make sure that they are not taking unauthorized breaks. Therefore, productivity in our office will soon increase.

Which one of the following is an assumption on which the manager's argument depends?

Answer: The gain in productivity that will result from reducing unauthorized breaks will exceed any loss in productivity caused by closer supervision.

Difficulty Level: 4

Rabies

Safety inspector: The number of laboratory samples of rabies virus sent through the university delivery service has recently grown dangerously high. We need to limit this use of the service.

Biologist: There is no need for a limit. The university delivery service has been handling rabies virus samples for 20 years with no accidents.

As a rebuttal of the safety inspector's claim, the biologist's reasoning is flawed in that it

Answer: Does not address the potential for harm that is posed by the recent increased in the number of samples sent through the service.

Difficulty Level: 1

Democratic Society

In a democratic society, when a political interest group exceeds a certain size, the diverse and sometimes conflicting economic interests that can be found in almost any large group of people tend to surface. Once these conflicting interests have surfaced, they can make it impossible for the political interest group to unite behind a common program. Yet to have the political impact necessary to influence legislation, a group must be united.

The statements above, if true, most strongly support which one of the following views?

Answer: A political interest group can become ineffective by expanding to include as wide a membership as possible.

Difficulty Level: 2

Video:
https://www.youtube.com/watch?v=YyeqyU_LHPM

G-H-J

The gu, the hu, and the jue are types of bronze libation vessels that were produced in China during the Shang dynasty, almost 4000 years ago. Close examination of authentic gu, hu and jue vessels reveals that they all bear incised patterns symbolizing the taotie, a mythological beast of greed. It must be true then that any bronze libation vessel that does not bear incised patterns symbolizing the taotie is not an authentic vessel produced in China during the Shang dynasty.

The argument makes which one of the following errors of reasoning?

Answer: Treating the fact that some members of a category possess a certain characteristic as sufficient evidence that possession of the characteristic is necessary for membership in that category.

Difficulty Level: 1

Video:
https://www.youtube.com/watch?v=K-wWaR3w6as

Diet Question

Frequently, people who diet to lose weight become trapped in a vicious cycle. When those people diet, they not only lose weight, but their bodies become used to fewer calories and become accustomed to functioning at that lower rate of caloric intake. As a result, when they stop dieting and go back to eating amounts of food that would have just maintained their weight in the days before the diet, they take in far more calories than they need. Those excess calories produce excess weight.

The passage above best supports which one of the following conclusions about people who diet to lose weight?

Answer: They must not go back to eating pre-diet amounts of food if they are to maintain their weight at the reduced level resulting from dieting.

Difficulty Level: 2

Video:
https://youtu.be/L6BBsUyMM_Y

Understanding the Impact of Additional Information

Sometimes you'll be asked to STRENGTHEN, WEAKEN or simply FIGURE OUT what additional information would be helpful to know.

1. A weakener or strengthener must affect the support for the conclusion.
- Beware of answer choices that are relevant to the general subject matter but relevant to the way the argument supports its conclusion.

Sufficient and Necessary Assumptions

Sufficient
In answering sufficient assumption questions, you need to find a link between the stated premises and the conclusion. Try to determine from the explicit parts of the argument what logical work that link needs to do. Finally, look among the answer choices for one that can do that logical work and that, taken along with the explicit premises, allows the conclusion to be properly inferred.

In trying to figure out what logical work the link needs to do, don't get too specific. Answer choice (A) was not the only possible sufficient assumption. An equally acceptable sufficient assumption would have been "People cannot feel secure if they have vague limits on their freedom." So don't approach the answer choices with too specific a view of what you're looking for.

When trying to identify a sufficient assumption, keep in mind that the correct answer must, when added to the argument's explicit premises, result in a conclusive argument; that is, in an argument that fully establishes its conclusion (provided that the explicit premises and the added assumption are all true).

Sample question prompts
Which one of the following, if assumed, enables the conclusion of the argument to be properly drawn?

The conclusion follows logically from the premises if which one of the following is assumed?

Necessary
A necessary assumption is an indispensable link in the support for the conclusion of an argument. Therefore, an argument will be ineffective if a necessary assumption is deemed to be false. This points to a useful test: to see whether an answer choice is a necessary assumption, suppose that what is stated in that answer choice is false. If under those circumstances the premises of the argument fail to support the conclusion, the answer choice being evaluated is a necessary assumption.

Test for necessary assumptions by asking whether the argument would fail if your answer choice is false. 

Denying the answer choice (by negating it) - if it causes the argument to fail means that you have found a necessary assumption.

Some points to consider
1. Identifying necessary assumptions is a matter of logically analyzing the structure of an argument
2. Identifying an assumption is a matter of probing the structure of an argument and recognizing hidden parts of that structure
3. An argument may have more than one necessary assumption but only one of them will appear in the answer choices. But the one that does appear may not be one that occurred to you when you analyzed the argument. So it is a good idea not to prejudge what the correct answer will be. Instead, keep an open mind and examine each of the answer choices in turn.


Sample question prompts
The argument relies on assuming which one of the following?

The argument depends on the assumption that

Which one of the following is an assumption required by the argument?

Necessary/Sufficient 2

Necessary is something that must occur for the second act to follow (but does not guarantee that Act 2 will occur).

For example, it is necessary to put food into your mouth before you can eat. You can't eat without first putting food into your mouth.

So in general, when you have a statement that expresses a necessary condition, it allows you to infer something in just two cases:

1. You can infer from knowing that if the necessary condition is not met that the thing it is the necessary condition for does not occur.

- If you don't buy a Powerball ticket, then you won't win the Powerball jackpot.

2. You can infer that the necessary condition is met from knowing that the thing it is the necessary condition for occurs.

- If you won the Powerball jackpot, then it means you bought a Powerball ticket.

Sufficient is something that guarantees that the second act follows.

Rain is sufficient to make the sidewalk wet.

If the sidewalk is dry then you know it didn't rain.

So in general, when you have a statement that expresses a sufficient condition, it allows you to infer something in just two cases:

1. If you know that the sufficient condition is met, then you can infer that the thing it is the sufficient condition for occurs

2. You can infer that the sufficient condition is not met from knowing that the thing it is the sufficient condition for does not occur

Necessary and Sufficient Conditions

Necessary Conditions:
If P is necessary for Q, then Q cannot be true unless P is true.

In other words:
Q is true only if P is true.
"P is necessary for Q because P being true is needed for Q to be true."

For example, what is necessary to get into a university.

1. You must be a human being (a bug can't get into a university)
2. You must submit an application (without an application, you can't get in)
3. Having decent grades (if you're a dummy then you won't get in)

Another example, what is necessary to win the Powerball

1. You must buy a ticket (without a ticket you can't win because you have no chance)

Necessary conditions represent things that must be in place for a certain outcome to occur but in and of itself does not guarantee that certain outcome. If that desired outcome occurs, however, the necessary condition was first met.


Sufficient Conditions:
If P is sufficient for Q, then P's being true is enough to make Q true.

In other words:
If P is true then Q is true.
"P is sufficient for Q because is P is all you need to get Q, P is enough to get Q."

For example, what is a sufficient condition to get into a university.

1. You are a super smart whiz kid who won the Nobel Peace Prize (the university wants you then)
2. You are the No. 1 athlete in the world (the university wants you then)

Another example, what is sufficient to have make the sidewalks get wet?

Rain - if it rains then it guarantees that the sidewalk will get wet. Of course there are other things that can cause the sidewalk to get wet (sprinkler system, water balloon, etc.) but just as long as there is rain that's enough to say that the sidewalk is going to get wet.


Something that is Necessary but not Sufficient: Steering a Car Well
1. Steering a car well is necessary for driving a car well. However, it is not sufficient for driving well. What if you steer like a boss but drive through a stop sign without obeying it?

Something that is Sufficient but not Necessary: Boiling a Potato
1. Boiling a potato is sufficient for cooking it. However, it is not necessary for cooking it as there are other ways in which you can cook a potato (microwave it, bake it in the oven, etc.)

Identifying Points on Which Disputants Hold Conflicting Views

This is a famous painting. Do you know what it is?

Mary: Computers will make more information available to ordinary people than was ever available before, thus making it easier for them to acquire knowledge without consulting experts.

Joyce: As more knowledge became available in previous centuries, the need for specialists to synthesize and explain it to nonspecialists increased. So computers will probably create a greater dependency on experts.

What do Mary and Joyce disagree about?

Step 1: Form a clear mental picture about what's going on.
Step 2: What does what each person say commit them to?

So Mary says "Computers will decrease our dependency on experts."

Joyce says "Computers will increase our dependency on experts."

Correct answer: M & J disagree over whether computers will increase the need for ordinary people seeking knowledge to turn to experts. Mary says no. Joyce says yes.

Some points to consider:
1. The evidence that two speakers disagree about a particular point ALWAYS comes from what they EXPLICITLY say.
2. Rely only on what a speaker explicitly says and on what can be properly inferred from that.
3. The incorrect answer choices are 1. two speakers agree or 2. the view of at least one of the speakers cannot be determined on what has been said.

What Can Be Concluded (MBT and Soft MBT)

What is supported by the body of available evidence? A and B conclusively lead to what?

You are looking for something that is guaranteed to be true by the information you have been given. In other words, something that MUST BE TRUE.

Example:

Any sale item that is purchased can be returned for store credit but not for a refund of the purchase price. Every home appliance and every piece of gardening equipment is on sale with selected construction tools.

Answer:

Home appliance, gardening equipment and the selected construction tools cannot be returned for cash. Store credit only. No piece of gardening equipment is returnable for a refund.

Some points to consider:

1. For some claim to logically follow from certain information, that information has to guarantee that the claim is true. It isn't enough for the information to strongly support the claim; it has to consluviely establish the claim.

2. Answer choices are often incorrect because they take things one step beyond what the evidence supports. The claim might be too sweeping, they might say "all" when the evidence supports only a "most". Or where a statement about "likely to be" is warranted, an incorrect answer choice might say "is". Or where a statement about "all known cases" is warranted, an incorrect answer choice might say "all cases."

3. A modest or limited claim can be a correct answer even if the information supports a stronger claim. For example, there will be a festival every month and there will be a festival in June are equal statements.

4. Incorrect answers to questions about what logically follows can be claims that receive some support but that nevertheless could be false even though all of the information is correct.

Soft Must Be True
Some questions ask you to identify a position that is supported by a body of evidence but not supported conclusively.

You generally get some information rather than an argument. Choose the answer that receives strong support for the information you're provided with and eliminate the answer choices that receive no significant support (the incorrect answer choices).

An example

People should avoid taking the antacid calcium carbonate in doses larger than half a gram, for despite its capacity to neutralize stomach acids, calcium carbonate can increase the calcium level in the blood and thus impair kidney function. Moreover, just half a gram of it can stimulate the production of gastrin, a stomach hormone that triggers acid secretion. 

Prediction: Don't use in doses of larger than half a gram. Why? Two reasons: 1. calcium in blood can impair kidney function and 2. gastrin can be created which in turn leads to acid secretion.

Correct answer choice: Half a gram of calcium carbonate can causally contribute to both the secretion and the neutralization of stomach acids.

Some points to consider
1. Base your judgment about whether or not a particular answer choice is supported strictly on the information that is explicitly provided in the passage.

2. Support for the correct answer does not have to involved all of the information provided.

Matching Patterns of Reasoning

1-2-a-1-2-3

How to do tackle these problems?

Get a solid intuitive grasp of the logical structure of the reference argument:

What is the conclusion and how do the premises fit together to support the conclusion?


Some tips
1. Similarity or dissimilarity in subject matter does not matter
2. Background material that is not a premise or conclusion does not matter
3. Order of the premises or conclusion does not matter

An example
Conclusion: Ash is unlikely to ever collect a stone not from Tanzania.
Premise 1: She only collects Tanzanite stones.
Premise 2: All known deposits of Tanzanite are in Tanzania.

Prediction
Conclusion: It is UNLIKELY (not definitely will not happen)

Conclusion: The owls will probably never eat an animal that lives outside the lagoon.
Premise 1: The diet of all the owls on Scrag Island consists entirely of frogs on the island.
Premise 2: The only frogs yet discovered on Scrag Island live in the lagoon.

Main Point

Question: Are eggs a dairy product?



Conclusion: Despite being sold in the dairy aisle, eggs are not a dairy product. 

Premise 1: Dairy is a product of the mammary gland of mammals. 

Premise 2: Dairy refers to milk and anything made from milk, like cheese, butter and yogurt. 

Premise 3: Eggs are not made from milk. They don't even come from a milk-producing animal.

Main Point: Look for a position that the argument as a whole is trying to establish.

If it is not the Main Point, then it is:

1. A statement that, either directly or indirectly, give reasons for that position.
2. Background information
3. Contextual information

50,000 Calories Challenge

I am probably the third guy from the right at the moment. Would like to get to the second guy.

During Q4 2016, I'm going to burn 50,000 calories. As a result, I should lose 10 pounds and drop from 165 to 155 (at a minimum) and hopefully drop to 150.

October 2-9

6765 burned, 43,235 more to go

October 10-16


October 17-23


October 24-30

Sulfur Fumes

Each of the following, if true, weakens the argument EXCEPT:

Prolonged exposure to sulfur fumes permanently damages one's sense of smell. In one important study, 100 workers from sulfur-emitting factories and a control group of 100 workers from other occupations were asked to identify a variety of chemically reproduced scents, including those of foods, spices, and flowers. On average, the factory workers successfully identified 10 percent of the scents compared to 50 percent for the control group.

Answer: The chemicals used in the study closely but not perfectly reproduced the corresponding natural scents.

It would be a problem if the "chemically reproduced scents" were nothing like the real thing. But the fact that they were at least close makes them good enough. This doesn't do enough to weaken the argument.

Trucks

Which one of the following is an assumption required by the auditor's reasoning?

Auditor: XYZ, a construction company, purchased 20 new trucks 3 years ago, and there is no record of any of those trucks being sold last year. Records indicate, however, that XYZ sold off all of its diesel-powered trucks last year. We can thus conclude that none of the 20 trucks purchased 3 years ago were diesel powered.

Answer: None of the 20 trucks was sold before last year.

Videoconferencing Equipment

The reasoning in the argument is flawed in that the argument

A recent magazine article argued that most companies that do not already own videoconferencing equipment would be wasting their money if they purchased it. However, this is clearly not true. In a recent survey of businesses that have purchased such equipment, most of the respondents stated that the videoconferencing equipment was well worth its cost.

Answer: relies on a sample that it is reasonable to suppose is unrepresentative of the group about which it draws its conclusion.

This is a sampling fallacy. The people surveyed (videoconferencing equipment owners) doesn't represent the opinion of all small companies.

Conditional Diagramming

The science teacher's statements provide the most support for which one of the following?

Science teacher: In any nation, a flourishing national scientific community (SC) is essential to a successful economy (SE). For such a community (SC) to flourish requires that many young people become excited (YE) enough about science that they resolve to become professional scientists. Good communication (GC) between scientists and the public is necessary to spark that excitement (YE).

SE --> SC

SC --> YE

YE --> GC

SE --> GC

G|C --> S|E

Answer: No national can have a successful economy unless at some point scientists have communicated well with the public.

We're going to need to diagram this one to see if it fits. "No" statements and "unless" statements are hard enough to diagram when we get just one, but here we get both. Here's a tip for when that happens: start with the "unless" (or until, without, or except). So, "if not" at some point scientists have communicated well, then no nation can have a successful economy. At this point, we don't need to do a "no torpedo"; we can just let the "no" negate that part of the diagram. So we end up with "NOT Good Communication --> NO Successful Economy." Sure enough, that matches up with the transitive structure of our diagram, just in contrapositive form. This is our correct answer!

Lake Champlain Hares

Each of the following, if true, supports the zoologist's reasoning EXCEPT:

Zoologist: In the Lake Champlain area, as the North American snowshoe hare population grows, so do the populations of its predators. As predator numbers increase, the hares seek food in more heavily forested areas, which contain less food, and so the hare population declines. Predator populations thus decline, the hare population starts to increase, and the cycle begins again. Yet these facts along cannot explain why populations of snowshoe hares everywhere behave simultaneously in this cyclical way. Since the hare population cycle is well correlated with the regular cycle of sunspot activity, that activity is probably a causal factor as well.

Answer: Local weather patterns that can affect species' population changes can occur both in the presence of sunspot activity and in its absence. 

This presents an alternate cause that is independent of the sun spot behavior (local weather patterns). Alternate causes ALWAYS weaken causal arguments, so this is the correct answer in this strengthen except question. 

Can You Be Neutral?

The argument's conclusion follows logically if which one of the following is assumed?

Some theorists argue that literary critics should strive to be value-neutral in their literary criticism. These theorists maintain that by exposing the meaning of literary works without evaluating them, critics will enable readers to make their own judgments about the works' merits. But literary criticism cannot be completely value-neutral. Thus, some theorists are mistaken about what is an appropriate goal for literary criticism.

Answer: If it is impossible to produce completely value-neutral literary criticism, then critics should not even try to be value-neutral.

This is the assumption we're looking for. It bridges the gap in the argument between actually doing something and trying to do something.

Heavier = More?

Which one of the following most accurately expresses the conclusion drawn in the consumer advocate's argument?

Consumer advocate: Even if one can of fruit or vegetables weighs more than another, the heavier can does not necessarily contain more food. Canned fruits and vegetables are typically packed in water, which can make up more than half the weight of the can's contents. And nothing stops unscrupulous canning companies from including more water per can than others.

Answer: The heavier of two cans of fruit or vegetables does not necessarily contain more food than the lighter of the two cans contains.

The heavier one could just contain more water. This is our main point from the first sentence.

John

Which one of the following, if true, most strengthens the argument?

John of Worcester, an English monk, recorded the sighting, on December 8, 1128, of two unusually large sunspots. Five days later a brilliant aurora borealis (northern lights) was observed in southern Korea. Sunspot activity is tpyically followed by the appearance of an aurora borealis, after a span of time that averages five days. Thus, the Korean sighting helps to confirm John of Worcester's sighting.

Answer: Only heavy sunspot activity could have resulted in an aurora borealis viewable at a latitude as low as that of Korea.

This is a big time strengthener. It eliminates alternate causes - in fact, it eliminates all other alternate causes! This one is a home run for our argument in the stimulus.

Wow, Really?

Which one of the following actions would be unethical according to the principle stated above?

It is unethical for government officials to use their knowledge of impending policies to financially benefit themselves if that knowledge is not available to the general public.

A Finance Department official, one of the few people who knew of a plan to tax luxury cars, bought a luxury car just before the plan was announced to the public in order to avoid paying the tax.

Have You Gotten Your Tonsils Removed?

The pediatrician's argument is most vulnerable to the criticism that it

Pediatrician: Swollen tonsils give rise to brathing problems during sleep, and the surgical removal of children's swollen tonsils has been shown to alleviate sleep disturbances. So removing children's tonsils before swelling even occurs will ensure that the children do not experience any breathing problems during sleep.

Answer: fails to consider the possibility that some breathing problems during sleep may be caused by something other than swollen tonsils.

Don't Jack It Up

Which one of the following is an assumption on which the argument depends?

From time to time there is public outcry against predatory pricing - where a company deliberately sells its products at prices low enough to drive its competitors out of business. But this practice clearly should be acceptable, because even after its competitors go out of business, the mere threat of renewed competition will prevent the company from raising its prices to unreasonable levels.

Answer: any pricing practice that does not result in unreasonable prices should be acceptable.

Stealing is Wrong

The reasoning in the lawyer's argument is flawed in that the argument

Lawyer: If you take something that you have good reason to think is someone else's property, that is stealing, and stealing is wrong. However, Myers had no good reason to think that the compost in the public garden was anyone else's property, so it was not wrong for Meyers to take it.

Answer: takes a condition that by itself is enough to make an action wrong to also be necessary in order for the action to be wrong.

Okay to Lie?

Which one of the following actions most clearly violates the principle stated?

One should not intentionally misrepresent another person's beliefs unless one's purpose in doing so is to act in the interest of that other person.

Answer: Ann told someone that Bruce thought the Apollo missions to the moon were elaborate hoaxes, even though she knew he did not think this; she did so merely to make him look ridiculous.

Decipher the Human Genetic Code?

Which one of the following most accurately expresses the conclusion of the ethicist's argument?

Ethicist: Robert Gillette as argued that because a thorough knowledge of genetics would enable us to cure the over 3,000 inherited disorders that affect humanity, deciphering the human genetic code will certainly benefit humanity despite its enormous cost. Gillette's argument is not persuasive, however, because he fails to consider that such knowledge might ultimately harm human beings more than it would benefit them.

Answer: Gillette's argument is unconvincing because it ignores certain possible consequences of genetic research.

Chocolate or Vanilla?

Which one of the following, if true, most strengthens the argument?

A recent taste test reveals that most people like low-fat chocolate ice cream as much as its full-fat counterpart. Previous tests with vanilla ice cream found that people tended to dislike low-fat versions, complaining of a harsher taste. Chemists point out that chocolate is a very complex flavor, requiring around 500 distinct chemical compounds to produce it. Hence, this complexity probably masks any difference in taste due to the lack of fat.

Answer: Vanilla is known to be a significantly less complex flavor than chocolate.

Children vs. Adults Learning Styles

Which one of the following most logically completes the consultant's argument?

Consultant: Children taught using innovative new educational methods learn to think more creatively than children taught using rote methods such as drills, but they are less adept at memorizing large amounts of information. Most jobs at Grodex Corporation require the ability to think creatively but do not require a strong ability to memorize. So Grodex Corporation should probably conduct its employee-training seminars using the innovative methods, because ________.

Answer: the effects of teaching methods in the education of adults are generally very similar to the effects of those methods in the education of children.