Christina: I disagree with your view, even though I agree that a shift in economic policy is needed. If one wants to teach a horse to jump fences, one should train it to jump lower heights first.
Speaker 1 Summary
Jorge’s conclusion is express through his rhetorical question - we should proceed with the necessary changes all at once to our economic policy all at once. He supports this conclusion by an analogy to jumping over a chasm, which is something we would do all in one leap.
Speaker 2 Summary
Christina’s conclusion is that we shouldn’t change economic policy all at once. We should proceed with smaller changes over time. This is supported by an analogy to teaching a horse to jump fences. We would train a horse to jump lower heights first and build up to greater heights.
Objective
We’re looking for a point of disagreement. The speakers disagree about the pace at which we should change economic policy. Jorge thinks we should do it all at once. Christina thinks we should do it more slowly.
A
a shift in economic policy is not needed
The speakers share the same opinion about this. Both think we need a shift in economic policy.
B
revising current economic policy incrementally is like teaching a horse to jump fences
Jorge doesn’t express an opinion about this. He doesn’t comment on Christina’s horse jumping analogy.
C
the faster current economic policy is revised, the less painful the initial changes will be
Neither expresses an opinion about this. Neither suggests there will be pain from initial changes or that faster revisions means less pain in the beginning.
D
the economic changes should not all be made at the same time
This is a point of disagreement. Jorge thinks economic changes should be made all at the same time. Christina believes they should not be made all at the same time.
E
the current economic situation is grave
The speakers share the same opinion about this (or have no opinion). Both agree that a shift in economic policy is needed. If that means the current situation is grave, then the speakers agree. If we don’t know whether the current situation is grave, then they have no opinion.
Marcie: A better use of the money would be for a public works project that would create jobs.
Speaker 1 Summary
Jessica believes that the budget surplus should be used only to increase government payments to unemployed people.
Speaker 2 Summary
Marcie argues that a better use of the surplus would be for a public works project that would create jobs
Objective
Disagreement: Jessica and Marcie disagree about how the surplus can be best spent
A
Using the budget surplus to increase government payments to those who are unemployed is putting the money to good use.
Jessica certainly agrees with this statement, but Marcie does not provide any opinion. While Marcie believes the money could be better spent, that does not mean she dislikes increasing government payments to unemployed people.
B
The public deserves to have jobs created when there are many people who are unemployed.
Jessica does not give an opinion on this. It is unclear whether Marcia would agree with this because there is no indication that “many people” are currently unemployed.
C
When there is a choice between increasing payments to the unemployed and funding a public works project, the latter should usually be chosen.
Both speakers do not give an opinion on this. The stimulus is purely related to how a budget surplus should be spent; this answer choice is far too broad for the speakers to give an opinion.
D
Creating jobs through a public works project will ultimately benefit the public.
Marcie certainly agrees with this, but Jessica does not mention any positive/negative sentiments about a public works project.
E
There is a better way to use the budget surplus than increasing government payments to those who are unemployed.
Jessica disagrees with this statement because she believes increasing government payments is best. Marcie agrees with this statement because she wants to fund a public works project with the surplus.
Summarize Argument: Phenomenon-Hypothesis
The author draws the hypothesis that looking for methane in a planet’s atmosphere is the most reliable way to tell whether or not that planet has life. This is because methane will disappear from the atmosphere unless it’s constantly replenished by living organisms’ biological processes. In other words, methane will only persist in the atmospheres of planets with methane-producing life. The author is claiming that where there is methane, there is life, and where there is no methane, there is no life.
Notable Assumptions
Based on the knowledge that only planets with life will have methane in their atmospheres, the author assumes that all planets with life will have methane in their atmospheres. This means that the author is assuming that all life produces methane.
A
There are other ways of detecting the presence of life on a planet.
This does not weaken the argument. Whether or not there are other ways to detect life on a planet doesn’t affect whether or not methane detection is the most reliable way. All the other methods could be unreliable, we don’t know.
B
Not all living beings have the ability to biologically produce methane.
This weakens the argument. The author uses “reliable” to mean that methane indicates life, and an absence of methane indicates no life. However, if some living beings don’t produce methane, there could be a planet with no methane that still has life.
C
We are incapable at present of analyzing a planet’s atmosphere for the presence of methane.
This does not weaken the argument. Whether or not detecting methane is practical doesn’t make a difference to whether or not it would be the most reliable means of detecting life.
D
Some living beings biologically produce only very small amounts of methane.
This does not weaken the argument. The author never specifies how much methane would be required to detect it in the atmosphere; maybe even the tiniest amount is enough. This is like a weaker version of (B), trying to trick you into thinking it does the same thing.
E
Earth is the only planet whose atmosphere is known to contain methane.
This does not weaken the argument. Just because we haven’t found other planets with methane in their atmospheres, that doesn’t make a difference to whether methane is a reliable indicator of life. It’s not as though we have another verified life-containing planet to test.
All potatoes naturally contain solanine, which is poisonous in large quantities. Domesticated potatoes contain only very small amounts of solanine, but many wild potatoes contain poisonous levels of solanine. Since most of the solanine in potatoes is concentrated in the skin, however, peeling wild potatoes makes them at least as safe to eat as unpeeled domesticated potatoes of the same size.
Summary
For a given size of potato, a peeled wild potato is at least as safe as an unpeeled domesticated potato. Why? Because in any potato, most of the solanine (which is poisonous) is contained in the skin.
Missing Connection
The conclusion draws a comparison between the safety of peeled wild potatoes and unpeeled domesticated potatoes. But the premises only allow us to compare between peeled and unpeeled potatoes of the same kind. (A peeled potato should have less poison than an unpeeled potato of the same kind.)
How to get from premises to conclusion? We need to know how solanine content actually compares between peeled wild potatoes and unpeeled domesticated ones. If we knew that the solanine content that’s left over in a peeled wild potato is no higher than the entire solanine content of a same-size unpeeled domesticated potato, we could reach the conclusion.
A
The proportion of a potato’s solanine that is contained in its skin is larger in wild potatoes than in domesticated potatoes.
This compares proportions, but we need to compare absolute quantities. How much solanine is actually left over in a peeled wild potato, and how does that compare to an unpeeled domesticated one? (A) doesn’t answer either of those questions.
B
The amount of solanine concentrated in the skin of a wild potato is large enough by itself to be poisonous.
This only tells us about the poison content of wild potato skin, which is irrelevant. We need to know the amount of solanine left over in a wild potato without skin, and how that compares to the amount in a domesticated potato with skin. (B) ignores both sides of the comparison.
C
There is no more solanine in a peeled wild potato than in an unpeeled domesticated potato of the same size.
This compares the solanine content of a peeled wild potato and a same-size unpeeled domesticated one, and confirms that the wild potato comes in at the same amount of solanine or less. So we can conclude that peeled wild potatoes are indeed at least as safe.
D
There are no poisonous substances in domesticated potatoes other than solanine.
This ignores wild potatoes, so it can’t help us reach the comparison in the conclusion. The fact that solanine is the only poison in domesticated potatoes doesn’t tell us how much poison is in a peeled wild potato, or how that compares to the poison in a domesticated potato.
E
Wild potatoes are generally much smaller than domesticated potatoes.
Irrelevant. The conclusion is only about wild and domesticated potatoes of the same size.
Summarize Argument: Phenomenon-Hypothesis
The experimenters hypothesize that diminished activity in the premotor cortex is a cause of hyperactivity. Their evidence is a study that shows adults with significantly less brain activity in the premotor cortex were hyperactive, while those with normal activity levels were not.
Notable Assumptions
Based on a mere correlation, the experimenters assumes that less brain activity in the premotor cortex causes hyperactivity. This means they assume that the relationship isn’t the reverse (i.e., hyperactivity causing less brain activity in the premotor cortex), and also that there isn’t some other, hidden cause that’s actually responsible for both hyperactivity and less brain activity in the premotor cortex.
A
Some of the nonhyperactive adults in the study had children who suffer from hyperactivity.
Perhaps their children had less brain activity in the premotor cortex. There’s no reason to assume it’s 100% hereditary.
B
The hyperactive adults who participated in the experiment varied in the severity of their symptoms.
Even if they varied in the severity of their symptoms, they all generally had lower levels of brain activity in the premotor cortex than other participants.
C
The neuropsychologists who designed the experiment were not present when the tests were performed.
This doesn’t cast doubt on the study. There’s no reason to believe those same neuropsychologists had to be present for the experiment to be performed correctly.
D
All of the hyperactive adults in the study had been treated for hyperactivity with a medication that is known to depress activity in some regions of the brain, while none of the nonhyperactive adults had been so treated.
While there’s a correlation between premotor cortex brain activity and hyperactivity, there’s no direct causal relationship. Instead, premotor cortex brain function is diminished by a treatment for hyperactivity.
E
The test was performed only on adults because even though the method by which the test measured brain activity is harmless to adults, it does require the use of radiation, which could be harmful to children.
It doesn’t matter what’s harmful to the participants. This is especially true since, according to this answer, the participants wouldn’t have been harmed by the radiation.