PrepTest 149, Section 1, Question 25

What we’re looking for

Working the answers

• A

  This is a valid chain, but it takes a different route. Among articles, being an academic work brings specialized terminology, and specialized terminology means not being widely read. So an academic article isn't widely read. A moves forward through two linked rules. It doesn't identify some things lacking a required feature and use that absence to rule out their membership in a category.

• B

  Improved work earns high grades, but high grades could also be given for work that was excellent all along. B starts with students receiving the result and assumes they met this particular condition for receiving it. The original instead identifies some shows missing the required result and correctly rules out the condition. B's direction produces an invalid inference rather than our valid one.

• C
  Correct

  Unbiased biographies correspond to groundbreaking popular series. Embarrassing facts correspond to critical acclaim. An unbiased biography must contain those facts, just as a groundbreaking popular series must receive acclaim.

  Some biographies lack the embarrassing facts. Those biographies therefore cannot be unbiased. That matches identifying some popular series without acclaim and concluding that those series aren't groundbreaking. In both arguments, 'not all' tells us there are some members missing the required feature, and that rules them out of the category.

• D

  The colleagues meet the stated condition: they are polite to Schwartz. The rule then guarantees he is polite to them. This correctly applies a rule to a whole group that meets its starting condition. Our argument works with some members missing the required outcome and concludes they lack the starting feature. D is valid, but it isn't that pattern.

• E

  This puts the missing feature on the wrong side. Being worth reading guarantees being worth buying. But a book not worth reading could still be worth buying for another reason, such as its value as a collectible. E wrongly rules out the result when the stated condition is missing. To match the original, it would need some books not worth buying and conclude that those books aren't worth reading.