Solar radiation is a leading cause of skin cancer. In Britain, skin cancer is more common on the right side...
GMAT Critical Reasoning : (CR) Questions
Solar radiation is a leading cause of skin cancer. In Britain, skin cancer is more common on the right side of the face than on the left. Some dermatologists hypothesize that this difference is due to drivers in Britain being directly exposed to solar radiation on the right side of the face more often than on the left since drivers there sit on the right side of the car and have a window on their right.
In evaluating the hypothesis, it would be most useful to determine whether
Passage Analysis:
| Text from Passage | Analysis |
| Solar radiation is a leading cause of skin cancer. |
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| In Britain, skin cancer is more common on the right side of the face than on the left. |
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| Some dermatologists hypothesize that this difference is due to drivers in Britain being directly exposed to solar radiation on the right side of the face more often than on the left since drivers there sit on the right side of the car and have a window on their right. |
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Argument Flow:
The argument starts with a general medical fact about solar radiation causing skin cancer, then presents a specific observation about uneven cancer patterns in Britain, and finally offers a hypothesis that explains this pattern through driving habits and car design.
Main Conclusion:
The hypothesis that British drivers get more skin cancer on the right side of their face because they sit on the right side of cars and are more exposed to solar radiation through the right window.
Logical Structure:
This is actually an explanatory hypothesis rather than a strong argument. The dermatologists are proposing that the observed cancer pattern (more right-side cases) can be explained by the driving setup in Britain (right-side driving position leading to more sun exposure on the right side). The structure is: Medical fact → Observed pattern → Proposed explanation for the pattern.
Prethinking:
Question type:
Evaluate - We need to think of assumptions underlying the hypothesis and create scenarios that would either strengthen or weaken the conclusion when taken to extremes
Precision of Claims
The hypothesis makes specific claims about frequency (more often), location (right side vs left side), and causation (driving position causes cancer difference). We need to test whether the driving explanation actually accounts for the cancer pattern.
Strategy
Since this is an evaluate question, we need to identify the key assumptions in the dermatologists' hypothesis and think of information that would either strongly support or strongly undermine their explanation. The hypothesis assumes that:
- driving is a major activity for people in Britain
- the right-side driving position actually leads to significantly more sun exposure
- there aren't other explanations for the right-side cancer pattern
We should look for ways to test these assumptions.
This tells us whether non-drivers develop skin cancer at all, but doesn't address the key issue of whether the right-side vs left-side pattern is related to driving. Even if many non-drivers get skin cancer, the hypothesis could still be correct if drivers show a more pronounced right-side pattern. This doesn't help us evaluate the specific driving-related explanation.
This compares British drivers' daylight driving time to drivers elsewhere, but we don't have information about cancer patterns in other countries to make this comparison meaningful. The hypothesis is specifically about the right vs left pattern in Britain, not about overall cancer rates compared to other countries. This information isn't directly useful for evaluating the hypothesis.
This directly tests the core assumption of the hypothesis by comparing cancer patterns between frequent drivers and people who rarely drive or ride in cars. If both groups show similar right-side cancer patterns, this would weaken the driving explanation since it suggests driving exposure isn't the determining factor. If frequent drivers show much more right-side cancer, this would strengthen the hypothesis. This comparison directly evaluates whether driving correlates with the observed cancer pattern.
This tells us about driving behavior after cancer diagnosis, which is completely irrelevant to evaluating whether driving caused the cancer pattern in the first place. The timing is wrong - we need information about exposure before cancer development, not behavior afterward.
This tells us about protective measures drivers take, but doesn't help us evaluate whether the right-side exposure pattern exists or correlates with cancer. Even if many drivers try to protect themselves, the hypothesis could still be correct if some sun exposure still gets through, especially if it's more on the right side.