Summary
Most serious students are happy.
Most serious students go to graduate school.
All graduate students are overworked.
Most serious students go to graduate school.
All graduate students are overworked.
Very Strongly Supported Conclusions
Most serious students are overworked.
Some happy students go to grad school.
Some happy students are overworked.
Some happy students go to grad school.
Some happy students are overworked.
A
Most overworked students are happy students.
Unsupported. We know that some overworked students are happy, but we don’t know if most are. Let’s say there are 100 serious students: 51 are happy and 51 go to grad school. One student must be in both groups, but the other 99 could only be in the “happy” or “grad school” group!
B
Some happy students are overworked.
Must be true. Over 50% of serious students are happy; over 50% of serious students go to grad school and are therefore overworked. Thus, there must be overlap. Let’s say out of 100 serious students, 51 are happy and 51 go to grad school/are overworked. One student must be both!
C
All overworked students are serious students.
Unsupported. We know that most serious students are overworked, but that doesn’t tell us anything about how many overworked students are serious!
D
Some unhappy students go to graduate school.
Unsupported. While we can’t properly infer from the stimulus that all grad students are happy (although we can infer that some are), we also can’t rule out that possibility.
E
All serious students are overworked.
Unsupported. We can infer that most serious students are overworked, but there’s no evidence in the stimulus to support that all serious students are overworked.
Summarize Argument
The editorialist concludes that raising highway speed limits would greatly decrease highway safety. This is because people who currently speed would obey the new limit, while people who currently obey the limit would increase their speed to the new limit.
Notable Assumptions
The editorialist assumes that highway safety decreases when people drive faster, despite the fact the new limit would increase the speed of traffic to a more uniform rate. This means the editorialist believes that speed outweighs uniformity when it comes to highway safety.
A
Some drivers who obey current speed limits would not change their speeds after the introduction of the new speed limits.
If this were the case, then some portion of traffic would be moving slower than the rest. But the editorialist never says uniformity is important.
B
Uniformity of speeds among vehicles is more important for highway safety than is a low average highway speed.
The editorialist is entirely concerned with speed, but what really matters is speed uniformity. If the limits were raised, everyone would be driving the same speed. Thus, highway safety would actually improve.
C
Most drivers who drive 10 to 20 percent faster than current speed limits have never been involved in a highway accident.
We don’t care who’s actually been in an accident. Speeders may cause accidents without actually being involved in them (i.e. by causing people to change lanes).
D
Some drivers who violate current speed limits would also violate higher speed limits.
If anything, this would help the editorialist’s argument. High speeds make highways less safe, and this tells us some people will be exceeding even the raised speed limits.
E
Most drivers who violate current speed limits determine their speeds by what they believe to be safe in the situation.
If highway speed limits were raised, then the editorialist doesn’t believe many people would be violating the speed limit anymore. We’re not interested in why people currently choose to violate the speed limit.