One way to compare chess-playing programs is to compare how they perform with fixed time limits per move. Given any two computers with which a chess-playing program is compatible, and given fixed time limits per move, such a program will have a better chance of winning on the faster computer. This is simply because the program will be able to examine more possible moves in the time allotted per move.

Summary
One way to compare chess-playing programs is to compare how they perform a fixed time limit per move. This comparison is done by using any two computers that can run the program and giving each computer a set time limit to make a move. The faster computer will have a better chance of winning because the program can examine more moves within the same span of time and pick the best possible move.

Strongly Supported Conclusions
If two computers are running the same chess-playing software, the computer that can analyze the most available moves within a given time limit is most likely to win.

A
If one chess-playing program can examine more possible moves than a different chess-playing program run on the same computer under the same time constraints per move, the former program will have a better chance of winning than the latter.
This sounds similar but presents a very different situation. This talks about two *different* programs running on the *same* computer. If there were two different programs, there would be many more confounding variables to make a comparison.
B
How fast a given computer is has no effect on which chess-playing computer programs can run on that computer.
The stimulus says that the speed of a computer dictates how many moves the computer can assess, but nothing says its speed has no bearing on what program it can run. For example, you probably couldn’t run a fancy program on a potato computer.
C
In general, the more moves a given chess-playing program is able to examine under given time constraints per move, the better the chances that program will win.
This captures exactly what the stimulus details. The faster computer can examine more moves and is thus better positioned to make better moves and win.
D
If two different chess-playing programs are running on two different computers under the same time constraints per move, the program running on the faster computer will be able to examine more possible moves in the time allotted.
This is a very different scenario than the stimulus. This answer choice has two different computers and two different programs. You can only reach the same conclusion under the same conditions presented in the stimulus.
E
If a chess-playing program is run on two different computers and is allotted more time to examine possible moves when running on the slow computer than when running on the fast computer, it will have an equal chance of winning on either computer.
There is no information on what would happen if a slower computer was given more time compared to a faster computer. You have to assume that the processing speed of the slower computer is exactly equal to the time difference given to the faster computer.

53 comments

Politician: Democracy requires that there be no restrictions on the ability of citizens to share their ideas freely, without fear of reprisal. Therefore the right to have private conversations, unmonitored by the government, is essential to democracy. For a government to monitor conversations on the Internet would thus be a setback for democracy.

Summarize Argument
The politician argues that it would harm democracy if a government were to monitor conversations. Why? Because for a democracy to work, people need to be able to freely share their ideas without worrying the government might take action against them. Unmonitored private conversations are essential to democracy.

Identify Argument Part
The referenced text supports the second sentence, which in turn supports the conclusion. Why is the right to private, unmonitored conversations essential to democracy? Because democracy requires free expression of ideas.

A
It is a claim for which no support is provided, and which is used to support only the argument’s main conclusion.
There’s certainly no support provided for the referenced text, but it doesn’t support the main conclusion. Instead, it supports a sub-conclusion, which in turn supports the main conclusion.
B
It is a claim for which no support is provided, and which is used to support a claim that is itself used to support the argument’s main conclusion.
The referenced text is definitely unsupported, which makes it a premise. It supports the second sentence, which in turn supports the main conclusion about democracy being harmed when the government monitors conversations.
C
It is a claim for which support is provided, and which is in turn used to support the argument’s main conclusion.
There’s no support for this claim. Nor does it support the main conclusion. Instead, it’s support for a sub-conclusion.
D
It is the argument’s main conclusion and is inferred from two other statements in the argument, one of which is used to support the other.
The argument’s main conclusion is the last sentence. The referenced text certainly isn’t inferred from the sub-conclusion and main conclusion.
E
It is the argument’s main conclusion and is inferred from two other statements in the argument, neither of which is used to support the other.
The referenced text isn’t the main conclusion. It also isn’t inferred from anything. It’s support for the second sentence, which is a sub-conclusion.

15 comments

The diet of Heliothis subflexa caterpillars consists entirely of fruit from plants of the genus Physalis. These fruit do not contain linolenic acid, which is necessary to the growth and maturation of many insects other than H. subflexa. Linolenic acid in an insect’s diet is also necessary for the production of a chemical called volicitin. While most caterpillar species have volicitin in their saliva, H. subflexa does not.

Summary

Most caterpillar species have volicitin in their saliva.

If an insect produces volicitin, then it must have linolenic acid in its diet.

Many insects need linolenic acid to grow.

*Physalis* plants don’t contain linolenic acid.

*H. subflexa* caterpillars only eat *Physalis* plants.

*H. subflexa* caterpillars don’t have volicitin in their saliva.

Very Strongly Supported Conclusions

Most caterpillar species have linolenic acid in their diets.

Most caterpillar species don’t eat only *Physalis* plants.

Many insects can’t grow and mature if they only eat *Physalis* plants.

A
H. subflexa caterpillars synthesize linolenic acid within their bodies.

Unsupported. *H. subflexa* caterpillars don’t get linolenic acid from their diets, but this doesn’t necessarily mean that they synthesize it within their bodies. They might just not need any linolenic acid or volicitin.

B
Most species of caterpillar have sources of linolenic acid in their diets.

Very strongly supported. Most species of caterpillar have volicitin in their saliva. And if an insect produces volicitin, then it must have linolenic acid in its diet. So most species of caterpillar have linolenic acid in their diets.

C
Any caterpillar that has linolenic acid in its diet has volicitin in its saliva.

Unsupported. If a caterpillar has volicitin in its saliva, then it must have linolenic acid in its diet. But this doesn’t necessarily mean that if a caterpillar has linolenic acid in its diet, then it must have volicitin in its saliva. (C) reverses the conditional claim.

D
A food source containing linolenic acid would be poisonous to H. subflexa caterpillars.

Unsupported. *H. subflexa* caterpillars only eat plants that don’t contain linolenic acid. But this doesn’t necessarily mean that plants that do contain linolenic acid are poisonous to them. They might just hatch on *Physalis* plants and never move to other plants.

E
No caterpillars other than H. subflexa eat fruit from plants of the genus Physalis.

Unsupported. Most caterpillars have linolenic acid in their diets. But this doesn’t mean that no other caterpillars eat *Physalis* plants. There might be others like *H. subflexa* that only eat *Physalis* plants, or some that eat *Physalis* plants and other plants with linolenic acid.


10 comments

After a hepadnavirus inserts itself into a chromosome of an animal, fragments of the virus are passed on to all of that animal’s descendants. A hepadnavirus fragment is present in a chromosome of the zebra finch and in precisely the same location in a corresponding chromosome of the dark-eyed junco. The fact that these two bird species diverged from each other about 25 million years ago therefore means that the hepadnavirus is at least 25 million years old.

Summarize Argument
The author concludes that the hepadnavirus present in the chromosomes of a zebra finch and dark-eyeed junco is at least 25 million years old. This is because after a hepadnavirus inserts itself into a chromosome of an animal, it’s based on to all of that animal’s descendants. In addition, the hepadnavirus is found in the same location in the corresponding chromosome of the finch and the junco. And, these two species diverged around 25 million years ago.

Notable Assumptions
The author assumes that having a hepadnavirus in the same corresponding location in the chromosome tells us something about when the hepadnavirus was inserted. The author also assumes the hepadnavirus didn’t insert itself into each bird’s chromosome more recently than 25 million years ago.

A
Viruses can affect the evolution of an organism and can thereby influence the likelihood of their diverging into two species.
This suggests viruses might have influenced the divergence of the two species. But this doesn’t suggest anything about the age of the hepadnavirus. Perhaps other viruses caused the species to diverge, and the hepadnavirus was inserted in each chromosome after divergence.
B
The chromosomes of the zebra finch and the dark-eyed junco contain fragments of no virus other than the hepadnavirus.
This tells us there’s no other virus in the chromosomes of the birds. But this doesn’t reveal anything about the age of the hepadnavirus.
C
When a virus inserts itself into an animal’s chromosome, the insertion occurs at a random spot.
This strengthens by casting doubt on the possibility that the virus inserted itself into each chromosome after the divergence 25 million years ago.
D
Many bird species other than the zebra finch and the dark-eyed junco contain fragments of the hepadnavirus.
The presence of the virus in other birds has no clear impact on how long the virus has been around.
E
The presence of a hepadnavirus in an animal species does not affect the likelihood of that species’ survival.
Whether the virus affects chances of a species’ survival has no clear impact on how long the virus has been around.

50 comments

Edgar: Some of the pumps supplying water to our region have been ordered shut down in order to protect a species of small fish. But it is absurd to inconvenience thousands of people for the sake of something so inconsequential.

Rafaela: You’re missing the point. The threat to that fish species is a sign of a very serious threat to our water supply.

Speaker 1 Summary

Edgar asserts that we shouldn’t shut down pumps supplying water to our region simply because those pumps threaten a small species of fish. The shut down would cause too much inconvenience for so little benefit.

Speaker 2 Summary

Rafaela’s implicit conclusion is that the decision to shut down the water pumps is a good idea. This is because the threat to the fish species is a sign of a threat to the water supply.

Objective

We’re looking for a point of disagreement. The speakers disagree over whether shutting down the pumps is a good idea and about whether the decision to shut down the pumps is designed only to protect the fish species. Edgar thinks the decision is just about the fish. Rafaela thinks it’s also about the water supply.

A
shutting down the pumps will actually inconvenience a large number of people

Rafaela doesn’t express an opinion. She doesn’t comment on inconvenience or say anything suggesting an opinion about it.

B
the survival of the fish species is the only reason for shutting down the pumps

This is a point of disagreement. Edgar thinks the shutdown is only related to protecting the fish. Rafaela thinks it’s about protecting the water supply.

C
species of small fish are inconsequential

Rafaela doesn’t express an opinion. She doesn’t comment on whether protecting small fish is important or unimportant. Her point is that the shut down also helps protect the water supply.

D
the order to shut down the pumps was legal

Neither speaker expresses an opinion. They don’t comment on the legality of the shutdown.

E
shutting down the pumps will be sufficient to protect the fish species

Neither speaker expresses an opinion. They don’t comment on whether the shutdown will successfully protect the fish.


13 comments

Archaeologist: Neanderthals, a human-like species living 60,000 years ago, probably preserved meat by smoking it. Burnt lichen and grass have been found in many Neanderthal fireplaces. A fire of lichen and grass produces a lot of smoke but does not produce nearly as much heat or light as a wood fire.

Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that Neanderthals probably smoked their meat. This is based on the fact that burnt lichen and grass have been found in many Neanderthal fireplaces, and fire made from lichen and grass produces lots of smoke, but not as much heat or light as a fire from wood.

Notable Assumptions
The author assumes that the Neanderthals did not burn the lichen and grass for heat, light, or other purposes besides smoking. The author also assumes that Neanderthals would not have used lichen/grass for heat/light if there existed a better material for that purpose.

A
In close proximity to the fireplaces with lichen and grass are other fireplaces that, evidence suggests, burned material that produced more heat than smoke.
This could strengthen the argument by showing that Neanderthals burned other material for heat, which suggests lichen and grass were not being burned for heat.
B
In the region containing the Neanderthal fireplaces in which lichen and grass were burnt, no plants that could be burned more effectively to produce heat or light were available 60,000 years ago.
This raises the possibility that Neanderthals burned lichen/grass for heat/light. Although wood can produce more heat/light, (B) tells us the Neanderthals didn’t have access to it. So, they might have used lichen/grass for heat/light because it was the best available material.
C
Some of the fireplaces containing burnt lichen are in regions in which lichen is not believed to have been plentiful and so would have had to have been brought in from some distance.
This suggests lichen was brought long distances. This is consistent with the theory that it was burned for its smoke.
D
There is clear evidence that at least some groups of Neanderthals living more recently than 60,000 years ago developed methods of preserving meat other than smoking it.
This concerns other groups living more recently that developed other methods of preserving meat. But the argument is about what conclusions we can draw about the Neanderthals who used the fireplaces around which burnt lichen and grass have been found.
E
The ability to preserve meat through smoking would have made the Neanderthal humans less vulnerable to poor periods of hunting.
If anything, this strengthens the argument by suggesting Neanderthals had a strong reason to preserve meat by smoking.

48 comments

Pundit: For many high school graduates, attending a university would be of no help in getting a corporate job. The attributes corporations value most in potential employees are initiative, flexibility, and the ability to solve practical problems. Many new high school graduates have these attributes already.

Summarize Argument
The author concludes that for many high school graduates, attending university would not help in getting a corporate job. This is because corporations value initiative, flexibility, and practical problem-solving ability the most out of all attributes, and many new high school graduates already have these attributes.

Identify and Describe Flaw
The author overlooks the possibility that university can increase one’s initiative, flexibility, and practical problem-solving ability, even if one already possesses those attributes. The author also overlooks the university can help with other attribute that are valued by corporations, even if those other attributes aren’t the most valued.

A
fails to establish that university graduates do not have initiative, flexibility, and the ability to solve practical problems
The argument doesn’t need to establish this, because the conclusion is only about high school graduates.
B
overlooks the possibility that corporations may require an attribute that potential employees can obtain only by attending a university
This possibility points out why attending university can still help high school graduates get a corporate job, even if they already have the attributes most valued by corporations. Perhaps the corporation requires a college degree, for example.
C
provides no justification for the presumption that corporations only hire employees who have initiative, flexibility, and the ability to solve practical problems
The author assumes that people who already have those attributes won’t increase their chances of getting hired by a corporation by attending university. This doesn’t require that corporations only hire people with those attributes.
D
takes for granted that the only reason that high school graduates go on to attend university is to improve their job prospects
The argument doesn’t make any assumptions about the high school graduates’ purposes in attending university. The argument is only about the effect of university on one’s chances of getting a corporate job.
E
takes for granted that initiative, flexibility, and the ability to solve practical problems are attributes that can be acquired through study
The author doesn’t assume that these attributes can be acquired through study. The author relies on high school graduates who already have those attributes. Whether they got those attributes through study or not has no impact.

4 comments

It is pointless to debate the truth of the law of noncontradiction, a fundamental logical principle according to which two statements that contradict each other cannot both be true. For a debate to be productive, participants must hold some basic principles in common. But the principles held in common in a debate over the law of noncontradiction would be much less certain than that law, so it matters little whether the law of noncontradiction can be defended on the basis of those principles.

Summarize Argument
The author states that there’s no point debating the truth of the law of noncontradiction, since a productive debate would require some agreement among the participants on basic principles. But since those common principles would be even less certain than the law of noncontradiction, it would be impossible to defend the law of noncontradiction using those principles.

Identify Conclusion
The conclusion is about the value of debating the law of noncontradiction: “It is pointless to debate the truth of the law of noncontradiction.”

A
It is pointless to debate the truth of the law of noncontradiction.
The author concludes that it’s pointless to debate the truth of the law of noncontradiction since a debate couldn’t be productive. The premises simply explain why this would be pointless.
B
Statements that contradict each other cannot both be true.
This is context about the law of noncontradiction. The rest of the author’s argument doesn’t support this statement.
C
The participants in a productive debate must hold at least some basic principles in common.
This is a premise that the author uses to demonstrate why debate would be pointless. Since the basic principles would be less certain than the law itself, no productive debate could ensue.
D
The law of noncontradiction is a principle that the participants in a productive debate must hold in common.
This doesn’t show up in the argument, and therefore can’t be the conclusion. This is a generalization about the law of noncontradiction that the author doesn’t make.
E
Any principles that could be used to defend the law of noncontradiction are less certain than it is.
This is a premise used to demonstrate the pointlessness of a debate about the truth of the law of noncontradiction. Since participants couldn’t adequately defend the principle with other shared principles, debate would be fruitless.

2 comments