Summary
A bacterial species will develop greater resistance within a few years to any antibiotics used against it. The only exception to this inevitable development of greater resistance is when the antibiotics eliminates the bacterial species completely. But, no single antibiotic now on the market can eliminate bacterial species X completely.
Strongly Supported Conclusions
If any single antibiotic currently on the market is used against bacterial species X, the species will develop greater resistance against that antibiotic.
A
It is unlikely that any antibiotic can be developed that will completely eliminate bacterial species X.
Unsupported. The stimulus tells us about antibiotics currently on the market. We don’t know about future antibiotics and their ability to kill bacterial species X completely.
B
If any antibiotic now on the market is used against bacterial species X, that species will develop greater resistance to it within a few years.
Strongly supported. We know no antibiotic currently on the market can kill X completely. So, if used against X, X will develop a resistance against that currently-on-the-market antibiotic.
C
The only way of completely eliminating bacterial species X is by a combination of two or more antibiotics now on the market.
Unsupported. We don’t know that this is the only way. Maybe another way is to develop a new antibiotic that can kill X completely. The stimulus doesn’t suggest this can’t be done.
D
Bacterial species X will inevitably become more virulent in the course of time.
Unsupported. The stimulus allows us to conclude that X will develop greater resistance to any currently-on-the-market antibiotic used against it. This doesn’t imply anything about the level of danger or harm (virulence) posed by X and whether it will change.
E
Bacterial species X is more resistant to at least some antibiotics that have been used against it than it was before those antibiotics were used against it.
Unsupported. We don’t know whether any antibiotics have ever been tried against X.
Reporter: This means, then, that if anyone in the study had athlete’s foot that was not cured, that person did not receive medication M.
Summarize Argument
The reporter concludes that, in a study testing medications for athlete’s foot, anyone who was not cured was not given medication M. This is based on the observation that, in the study, everyone whose athlete’s foot was cured received medication M.
Identify and Describe Flaw
This is a cookie-cutter flaw: confusing sufficient and necessary conditions. In the study, everyone whose athlete’s foot was cured received medication M, making medication M necessary to have been cured in this study. However, that doesn’t mean medication M is sufficient to cure every case that it was used to treat. In other words, it’s possible that not everyone who received medication M was cured.
A
The reporter concludes from evidence showing only that M can cure athlete’s foot that M always cures athlete’s foot.
The argument confuses sufficient and necessary conditions. Only M cures athlete’s foot, making it necessary for curing athlete’s foot in the study. However, that doesn’t mean it’s sufficient to always cure athlete’s foot.
B
The reporter illicitly draws a conclusion about the population as a whole on the basis of a study conducted only on a sample of the population.
The reporter only draws a conclusion about the study, not the population as a whole.
C
The reporter presumes, without providing justification, that medications M and N are available to people who have athlete’s foot but did not participate in the study.
The reporter doesn’t make any claims about the availability of the medications, only their effects on athlete’s foot in the study.
D
The reporter fails to allow for the possibility that athlete’s foot may be cured even if neither of the two medications studied is taken.
The reporter is only drawing a conclusion about the efficacy of medication M based on the study, and doesn’t need to account for the possibility that athlete’s foot could be cured in other ways.
E
The reporter presumes, without providing justification, that there is no sizeable subgroup of people whose athlete’s foot will be cured only if they do not take medication M.
The reporter is only discussing the study, where every participant whose athlete’s foot was cured had received M. The possibility of this kind of subgroup is irrelevant to M being necessary to cure athlete’s foot in the study.
Summarize Argument
The author concludes that it’s unlikely the airport will be built. This is based on the following:
If most of Dalton’s residents favor the proposal, the airport will be built.
It’s unlikely most of Dalton’s residents would favor the proposal. (This is a subsidiary conclusion based on the fact that most residents believe the airport would create noise problems.)
Identify and Describe Flaw
The author confuses a sufficient condition with a necessary condition. Although most of Dalton’s residents’ favoring the proposal is sufficient for the airport to be built, that doesn’t mean it’s necessary. It’s possible for the airport to be built even if most residents don’t favor the proposal.
A
treats a sufficient condition for the airport’s being built as a necessary condition
The author treats a sufficient condition for the airport’s being built (majority of Dalton’s residents favoring proposal) as a necessary condition. This overlooks that the airport can be built even if most Dalton residents don’t favor the proposal.
B
concludes that something must be true, because most people believe it to be true
Although the author does point out that most people believe the airport would create noise problems, the author does not conclude that the airport would create noise problems.
C
concludes, on the basis that a certain event is unlikely to occur, that the event will not occur
The author’s conclusion is that the airport is “unlikely” to be built. The conclusion does not assert that the airprot “will not” be built.
D
fails to consider whether people living near Dalton would favor building the airport
Whether people living near Dalton would favor building the airport doesn’t matter, because we care about the majority of Dalton residents. People living near Dalton are not residents of Dalton.
E
overlooks the possibility that a new airport could benefit the local economy
The author’s reasoning attempts to apply a conditional. Whether there could be benefits to the economy doesn’t relate to the author’s misinterpretation of the conditional. Also, the possibility of benefits doesn’t suggest Dalton’s residents would favor the proposal.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that drivers feel possessive of their parking spots, and increasingly possessive when other drivers want their parking spots.
Notable Assumptions
The author believes that the drivers took more time leaving their spots when other cars were around because they were possessive of their spots. He therefore assumes there’s not some other factor (i.e. the fact there’s a car nearby as they’re leaving the spot) preventing drivers from leaving their spots as quickly as they would when there aren’t other cars around.
A
The more pressure most drivers feel because others are waiting for them to perform maneuvers with their cars, the less quickly they are able to perform them.
Drivers aren’t possessive when other cars are around. They’re simply feeling pressure, which makes them slow down while leaving their spots.
B
The amount of time drivers spend entering a parking space is not noticeably affected by whether other drivers are waiting for them to do so, nor by whether those other drivers are honking impatiently.
We don’t care what happens when drivers enter a spot. We care what happens while they’re leaving a spot.
C
It is considerably more difficult and time-consuming for a driver to maneuver a car out of a parking space if another car waiting to enter that space is nearby.
This explains why drivers took longer to leave the space than when no cars were waiting, but it doesn’t explain why honking intensified the effect. We need to know why that caused drivers to slow down even more.
D
Parking spaces in shopping mall parking lots are unrepresentative of parking spaces in general with respect to the likelihood that other cars will be waiting to enter them.
We don’t care about how frequently this scenario occurs.
E
Almost any driver leaving a parking space will feel angry at another driver who honks impatiently, and this anger will influence the amount of time spent leaving the space.
Even without the honking, drivers still took longer to leave when another car was waiting for the spot. We need to explain why that is.