LSAT 103 | Section 2 | Logical Reasoning: Q20

LR Question 20 Explanation

QUESTION TEXT: Martha’s friend, who is very knowledgeable about…

QUESTION TYPE: Flawed Parallel Reasoning

CONCLUSION: Martha thinks there must be edible daisies that taste good.

REASONING: Daisies are a type of chrysanthemum. There are some chrysanthemums that are edible and taste good.

Another way of putting it is: Some chrysanthemums are daisies, and some chrysanthemums are edible and tasty.

ANALYSIS: How’s this argument? Some mammals are humans, and some mammals can fly (e.g. bats). Therefore some humans can fly.

The flaw is: Some members of the group are A, and some are B. That doesn’t mean some A’s are B’s.

___________

1. The city chorus could be renowned (well known) for terrible singing. This is a bad argument, but the flaw is different.
2. This is a good argument. Everyone in the group is an avid reader, so Rolfe is.
3. CORRECT. This is a bad argument,and the flaw is the same, though it’s worded a bit differently. You can’t combine two “some” statements. Some of the debate team are good and some of them are Noriko’s sisters. But that doesn’t mean the two groups overlap.
4. This is a good argument. Actually, the conclusion could be even stronger. It’s definitely true that most of Leon’s friends are quite strong, because all good swimmers are.
5. You can write a book on good writing without being a good writer. In fact, it’s quite possible to write a bad book on good writing.
    
   This isn’t the same flaw as the stimulus. There are no overlapping some statements. There’s just a mistake about what it takes to write a book on writing.

Recap: The question begins with “Martha’s friend, who is very knowledgeable about”. It is a Flawed Parallel Reasoning question. Learn more about LSAT Flawed Parallel questions in our guide to LSAT Logical Reasoning question types.