Though sucking zinc lozenges has been promoted as a treatment for the common cold, research has revealed no consistent effect....
GMAT Critical Reasoning : (CR) Questions
Though sucking zinc lozenges has been promoted as a treatment for the common cold, research has revealed no consistent effect. Recently, however, a zinc gel applied nasally has been shown to greatly reduce the duration of colds. Since the gel contains zinc in the same form and concentration as the lozenges, the greater effectiveness of the gel must be due to the fact that cold viruses tend to concentrate in the nose, not the mouth.
In order to evaluate the argument, it would be most helpful to determine which of the following?
Passage Analysis:
| Text from Passage | Analysis |
|---|---|
| Though sucking zinc lozenges has been promoted as a treatment for the common cold, research has revealed no consistent effect. |
|
| Recently, however, a zinc gel applied nasally has been shown to greatly reduce the duration of colds. |
|
| Since the gel contains zinc in the same form and concentration as the lozenges, the greater effectiveness of the gel must be due to the fact that cold viruses tend to concentrate in the nose, not the mouth. |
|
Argument Flow:
The argument starts by establishing that zinc lozenges don't work consistently for colds, then introduces evidence that zinc gel does work when applied nasally. Since both contain the same zinc, the author concludes the difference must be due to where cold viruses are located.
Main Conclusion:
The zinc gel is more effective than lozenges because cold viruses concentrate in the nose rather than the mouth.
Logical Structure:
The author uses process of elimination reasoning: if both treatments have identical zinc but different results, then the location of application must explain the difference. This assumes that virus location is the key factor determining treatment effectiveness.
Prethinking:
Question type:
Evaluate - We need to find information that would help us determine whether the author's conclusion is correct or not. The author claims that zinc gel works better than lozenges because cold viruses concentrate in the nose, not the mouth.
Precision of Claims
The author makes a specific causal claim about location - that the gel's superiority is 'due to the fact that cold viruses tend to concentrate in the nose, not the mouth.' This is a precise claim about where viruses are located and how location affects treatment effectiveness.
Strategy
For evaluate questions, we need to think of assumptions the author makes and create scenarios that would either strongly support or strongly undermine the conclusion when taken to extremes. We should focus on the gap between the evidence (gel works better than lozenges) and the explanation (because viruses are in nose, not mouth).
Whether zinc is effective only against colds, or also has an effect on other virally caused diseases. This doesn't help evaluate the argument because we're not comparing zinc's effectiveness across different diseases. We're specifically trying to understand why zinc gel works better than zinc lozenges for the same condition (colds). Information about zinc's effectiveness on other viral diseases is irrelevant to explaining the difference between these two cold treatments.
Whether there are remedies that do not contain zinc but that, when taken orally, can reduce the duration of colds. This information about other non-zinc oral remedies doesn't help us evaluate why zinc gel is more effective than zinc lozenges. We're trying to understand the specific difference between two zinc-based treatments, not compare zinc to completely different types of treatments.
Whether people who frequently catch colds have a zinc deficiency. This addresses a general relationship between zinc deficiency and cold susceptibility, but it doesn't help evaluate the author's specific claim about why nasal application is more effective than oral application. The argument isn't about zinc deficiency - it's about delivery method and virus location.
Whether either the zinc gel or the lozenges contain ingredients that have an impact on the activity of the zinc. This directly evaluates the author's key assumption. The author assumes that since both treatments have the same zinc 'form and concentration,' any effectiveness difference must be due to application location. However, if the treatments contain different inactive ingredients that enhance or inhibit zinc's activity, then the effectiveness difference might be due to these other ingredients rather than virus location. This information would help determine whether the author's location-based explanation is correct or whether there's an alternative explanation involving ingredient interactions.
Whether the zinc gel has an effect on the severity of cold symptoms, as well as on their duration. The argument already establishes that zinc gel reduces cold duration. Information about symptom severity doesn't help evaluate the author's explanation for why gel is more effective than lozenges. We need information that tests the location-based reasoning, not additional effects of the gel.