LR Drill Set 6, Question 4
Medical student: Tissue samples from the livers of(57 more words not shown)
The flawed reasoning in the(14 more words not shown)
- AJudicial interpretations of(55 more words not shown)
- BApples imported from(44 more words not shown)
- CA certain kind(45 more words not shown)
- DThe patented MV-2000(51 more words not shown)
- EThe windows that(48 more words not shown)
Reading the argument
We can rule out disease X. Why are we ruling out every liver disease?
Every patient with X has the unusual cell structure, so its absence is enough to exclude X. That part works. But the other statement only says that seeing the unusual structure means some liver disease is present. It never says every liver disease produces that structure.
Imagine disease Y affects the liver in a different way. A patient could have Y without showing the structure associated with X. The sample would then satisfy everything we were told while still coming from a diseased liver.
For the parallel, we need three roles: a specific category such as disease X, a feature such as the cell structure, and a broader category such as liver disease. Every member of the specific category has the feature, and the feature occurs only within the broader category. Then the feature is absent, and the argument correctly excludes the specific category but incorrectly excludes the entire broader category too.
What we’re looking for
An answer can put those premises in a different order. What matters is keeping their roles and the absent feature straight.
Working the answers
- A
The evidence describes interpretations as usually closer to legislators' intentions. The medical argument uses exceptionless relationships: X always brings the structure, and the structure never occurs without liver disease. A also transfers a description from an interpretation to the lawmakers' intentions; it doesn't use an absent feature to exclude both a specific and a broader category.
- B
This compares how well two groups of apples sell and adds a fact about consumer familiarity. We don't have a feature possessed by every member of one category and found only within a broader category. Nor does the conclusion make the matching two exclusions. Not knowing that these apples belong to either familiar group doesn't show they will sell badly, but that is a different mistake.
- C
Moles fit disease X, fungus fits the unusual cell structure, and animal pests fit liver disease. The opening relationships match. But this lawn has the fungus. Our sample lacks the unusual structure. C uses the presence of the feature to select a specific cause; the original uses its absence to rule out too broad a category. Matching the first two statements isn't enough.
- DCorrect
Space-Smart luggage corresponds to disease X, the MV-2000 lock to the unusual structure, and Bagco products to the broader liver-disease category. Every Space-Smart piece has the lock, and only Bagco products have it.
The suitcase lacks the lock, so it cannot be Space-Smart. That valid exclusion matches ruling out X. But Bagco might sell another suitcase or a handbag without this lock. Excluding all Bagco products therefore repeats the unsupported exclusion of every liver disease. The premises are reordered, but the complete pattern is the same.
- E
This says the builder's own windows meet certain standards, then assumes a competitor's windows must be worse. A competitor could buy equally good windows and inspect them just as carefully. That is an unsupported comparison with a different maker, not the specific-category, feature, broader-category pattern we need.
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