LSAT 144 | Section 3 | Logical Reasoning: Q10

LR Question 10 Explanation

QUESTION TEXT: Advertisement: VIVVY, a video-based foreign language course…

QUESTION TYPE: Flawed Parallel Reasoning

CONCLUSION: VIVVY is a good program.

REASONING: Three people have had success with VIVVY.

ANALYSIS: This is an unusually stupid argument, though it’s very common in advertising.

Suppose that 3,000,000 used VIVVY. Amy, Matt and Evelyn went on to become successful, and the other 2,999,997 students became hobos. Yikes. Would you have your child use VIVVY?

For parallel reasoning, you need to find an abstract way to describe the argument, then find the answer that matches that description. Here, the argument extrapolates from a small sample without indicating how many people the sample was taken from.

___________

1. CORRECT. This works. We have no idea how many people play the lottery. It’s quite possible that Annie, Francisco and Sean won due to chance and not due to their good luck charms.
2. This is very different. Here, Jesse is in the group of three people, and the conclusion is about Jesse. In the stimulus the conclusion was about everyone.
3. This makes a different error. It confuses necessary and sufficient. Yes, we can expect that those three will be laid off, since everyone hired in the past year will be laid off. But maybe many others will be laid off as well – we can’t conclude that these three will be the only victims of layoffs.
4. This is like B. The evidence and the conclusion concerns only the group of three people.
   In the argument, evidence from three people
   was used to make a claim about everyone who uses VIVVY.
5. This is a flawed argument, but it’s a different flaw. Just because most people get jobs, you can’t say that those three definitely will get jobs.
   Here, evidence from the whole university is used to make a claim about the group of three. In the stimulus, evidence from the group of three was used to make a claim about all users of VIVVY.