Martha’s friend, who is very knowledgeable

Answer choices

1. A

   Bad Conclusion Match10% picked this

   Jeanne is a member of the city chorus, and the city chorus is renowned. So Jeanne

   We can tell this is off the mark because it lacks the symbol repetition of the original. If we're saying "J is a part of the city chorus group, and the city chorus group has the trait of being renowned", then the matching conclusion would say something like, "J is a renowned singer". That would still be off somewhat, but closer. But since this argument is using a different idea in the conclusion, we know this doesn't match up. (excellent vs. renowned = skilled vs. famous)

   10%
2. B

   Bad Premise Match Valid Logic7% picked this

   Rolfe belongs to the library reading group, and all members of that group are avid readers. So Rolfe

   We were looking for this: P1: All A's are B (or A is a member of B) P2: Some B's are X C: Some A's are X And this argument is giving us this: P1: Rolfe is a member of the library group. P2: All library group members are X C: Rolfe is X. That's a valid argument! The original argument was flawed because some chrysanthemums are palatable and some aren't (and it's possible that daisies are entirely among the ones that aren't). In this case, every single library group user is an avid reader, so we know that every member is an avid reader.

   7%
3. C

   Correct69% picked this

   Some of Noriko’s sisters are on the debate team, and some members of the debate team are poor students. So at least one of

   Why this is right

   This matches our formula nicely. P1: Some A's are B Some N-sisters are on debate. P2: Some B's are X Some debate are poor students. C: Some A's are X Some N-sisters are poor students. Just like, P1: Some A's are B Some daisies are chrysanthemums. P2: Some B's are X Some chrysanthemums are palatable. C: Some A's are X Some daisies are palatable.

   Skill tested: Parallel Flaw · how this choice captures the argument's function is the move to repeat next time.

   69%
4. D

   Weak Premise Match Valid Logic8% picked this

   Most of Leon’s friends are good swimmers, and good swimmers are quite strong. So it is likely that at least some of

   The quantifiers on the two premises are off, which makes the argument actually have a pretty valid conclusion. P1: Some A's are B Most of L-friends are good swimmers. P2: Some B's are X All good swimmers are quite strong. C: Some A's are X Some of L-friends are quite strong. If we say "most of Paul's friends are NBA players, and NBA players are quite tall. Thus, some of Paul's friends are quite tall", that seems like valid logic.

   8%
5. E

   Weak Premise Match Bad Conclusion Match6% picked this

   Many of Teresa’s colleagues have written books. Most of the books they have written are on good writing. So some of

   The quantifiers on the two premises are off, which already make this inferior to the correct answer. P1: Some A's are B Many of T-colleagues have written books. P2: Some B's are X Most books written by T-colleagues are on the subject of good writing. C: Some A's are X Some of T-colleagues are good writers. But the conclusion is also a bad match. It is a flawed conclusion, because you can write a book on good writing without being a good writer yourself. But that's a different flaw. This argument introduces a new concept into the conclusion. The original argument did not.

   6%