Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that the boulder was probably deposited in its location by a glacier. This is based on the fact that the boulder is volcanic, but the surrounding rock is sedimentary. In addition, we know the area had southward-moving glaciers during the last ice age.
Notable Assumptions
The author assumes that there’s no other more likely source of the boulder besides the glaciers that were moving southward during the last ice age.
A
Most boulders that have been moved by glaciers have not been moved more than 100 miles.
Even if most boulders moved by glaciers didn’t travel as far as this one did, that doesn’t undermine the support provided by the specific reasons offered for why this boulder was moved by glaciers. Most other boulders might not be volcanic within sedimentary rock.
B
The closest geological source of volcanic rock is 50 miles south of this boulder.
We have no reason to think the boulder must have come from the closest source. Maybe there’s a source north of the boulder that’s several hundred miles away, and the boulder was carried south by a glacier.
C
The closest geological source of volcanic rock is 50 miles north of this boulder.
We have no reason to think the boulder must have come from the closest source. Maybe there’s a source north of the boulder that’s several hundred miles away, and the boulder came from that source.
D
There are no geological sources of volcanic rock north of this boulder.
This makes the author’s hypothesis less plausible. If there are no geological sources of volcanic rock north of the boulder, it’s difficult to explain how a southward-moving glacier could have deposited the boulder in its current location. Where would the boulder have come from?
E
No other boulders of volcanic origin exist within 50 miles of this boulder.
Perhaps volcanic boulders are rare. This doesn’t shed light on the source of the volcanic boulder that we’re talking about.
Frank: What you conclude is itself a general rule. If we assume that it is true, then there is at least one general rule that has no exceptions. Therefore, you must withdraw your conclusion.
Summarize Argument: Counter-Position
Frank concludes that Lance is wrong to claim that “every general rule has at least one exception.” This is because, according to Lance’s claim, Lance’s own general rule would need to have an exception. In other words, if Lance’s claim is true then not every general rule has at least one exception, in which case Lance’s claim cannot be true.
Describe Method of Reasoning
Frank counters Lance’s claim by pointing out that it is self-contradictory and cannot be logically true. As Frank points out, Lance’s general rule that “every general rule has at least one exception” entails that this rule itself must have at least one exception. If Lance’s rule has an exception, then logically, there must be some general rule with no exception, which would make Lance’s rule false.
A
demonstrating that Lance assumes the very thing he sets out to prove
Frank doesn’t demonstrate that Lance assumes the point that he is trying to prove. Instead, Frank demonstrates that Lance’s point is self-contradictory and therefore invalid.
B
showing that Lance’s conclusion involves him in a contradiction
Frank shows that Lance’s conclusion is self-contradictory, because in following the chain of inferences from Lance’s rule, one must end up breaking that rule.
C
showing that no general rule can have exceptions
Frank doesn’t claim that no general rule can have exceptions, only that Lance’s assertion that every general rule must have an exception is invalid.
D
establishing that experience teaches us the opposite of what Lance concludes
Frank doesn’t claim that the opposite of Lance’s conclusion is true, only that Lance’s conclusion is invalid. Frank also never talks about what experience teaches us.
E
showing that it has no implications for any real cases
Frank doesn’t bring up real cases in his argument. He only shows that Lance’s conclusion is logically contradictory.
"Surprising" Phenomenon
While heart attacks are most likely to happen on Mondays since people are stressed for the work week, unemployed retirees are also most likely to have heart attacks on Mondays.
Objective
The right answer will be a hypothesis that explains why unemployed retirees suffer heart attacks at higher rates on Mondays than the other days of the week. Either this answer will link unemployed retirees with stressed workers, or else give some other reason why Monday is a particularly likely day for heart attacks.
A
Because they associate Monday with work, retired people are more likely to begin large projects on Mondays.
After a lifetime of starting work on Monday, retired people begin large projects on Monday. This is stressful for them, hence why they too are more likely to suffer heart attacks on Monday than other days of the week.
B
Many retired people take up part-time jobs after they retire from their careers.
Do these part-time jobs start on Monday, too? This doesn’t tell us, so it can’t be right.
C
People seldom change their dietary and other health habits after retirement.
Mondays are conducive to heart attacks because of stress. Diet and health habits don’t factor into the equation, at least not according to the stimulus.
D
Stress is the major factor influencing the risk of heart attack.
We don’t know if retired people are stressed, and we have no reason to believe they’re more stressed on Mondays than other days. This doesn’t help.
E
Unemployed retired people are even more likely to have heart attacks than are people who have jobs.
We need an explanation. This simply gives us a fact that doesn’t clear anything up as to why retirees also suffer relatively more heart attacks on Mondays.
Summarize Argument
The psychologist concludes that people who are very overconfident are more likely to start businesses than people who aren’t as overconfident. This is because, according to a study, entrepreneurs are more likely than business managers to be overconfident.
Notable Assumptions
The psychologist assumes that overconfidence makes it more likely that someone becomes an entrepreneur, rather than that being an entrepreneur makes it more likely one will be overconfident. The psychologist also assumes that the business managers in questions hadn’t attempted to start businesses and lost confidence as a consequence.
A
The questions asked of the entrepreneurs and business managers included personal, political, and business questions.
We don’t care what kind of questions had been asked. We want to strengthen the relationship between overconfidence and starting a business.
B
At least some of the entrepreneurs surveyed had accurately determined before attempting to start their businesses what the odds were against their attempts being successful.
We don’t care if entrepreneurs had accurately determined their odds. Most people know starting businesses is always a risky decision.
C
Another survey showed that degree of confidence was highly correlated with success in business.
We don’t care. The psychologist never claims that overconfident is what makes entrepreneurs successful.
D
The business managers who were most overconfident were found to have attempted to start businesses in the past.
Overconfident business managers had tried to start businesses in the past, which strengthens the relationship between overconfidence and entrepreneurship. This moreover suggests that entrepreneurship doesn’t itself cause overconfidence.
E
How confident each person surveyed was that his or her answers to the questions asked were correct corresponded closely to that person’s confidence in his or her business acumen.
The psychologist doesn’t say anything about business acumen. We care about the relationship between overconfidence and taking the risk to start a business.