PrepTest 155
[lcid:3717] Prep Test 155 LSAT — Logical Reasoning — S2
Logical reasoning
Question prompt
Although smaller class sizes
Remaining source text redacted.
Why the credited answer is right
Credited answer: B
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Strengthen with Necessary Premise Questions
Answer choices
-
AReducing class size is Remaining source text redacted.
Why choice A is not credited
Incorrect. This answer is too extreme to be necessary. Reducing class size doesn't have to be extremely expensive for the argument to work, just more expensive than it's worth. -
BDollar for dollar, efforts Remaining source text redacted.
Why choice B matches the stem
Correct. Argument or Facts:
Argument
Valid or Flawed:
Flawed
Question Type:
Strengthen with Necessary Premise
Stimulus Summary:
While popular, decreasing class sizes costs a lot and has only small benefits. Since we should be doing cost-benefit tests for how we spend funding on education, it would be better to spend that money on better teachers.
Answer Anticipation:
This argument selects one option (better teachers) over another (smaller class sizes). While the argument analyzes the costs and benefits of smaller classes, it doesn't do the same for bette teachers. In order to reach the conclusion that the money is better spent on better teachers, the author needs to establish that better teachers come out ahead of smaller classes in the cost-benefit analysis.
Answer Explanation:
This answer is necessary, since the argument relies on recruiting better teachers having a larger positive impact per dollar spent to work. If, dollar for dollar, recruitments efforts don't yield larger improvements than reducing class sizes, the argument falls apart since there's no reason to do the former over the latter.
Key Takeaway:
When an argument concludes that one option is better than another, make sure that the premises give enough information to establish that comparison. Here, the argument establishes the criteria for the comparison (cost effectiveness), and talks about that criteria for one option (reducing class sizes), but not the other option. The correct answer, therefore, will likely talk about the compared criterion for that option. -
CBecause reducing class size Remaining source text redacted.
Why choice C is not credited
Incorrect. This answer is out of scope by talking about popularity (which is only mentioned as a counterpoint) and comparing it to most other policies, when the argument only cares about the two policies. -
DReducing class size is Remaining source text redacted.
Why choice D is not credited
Incorrect. If anything, this answer calls the argument into question by saying that there should be a focus on reducing class size in order to accomplish the other goal. Additionally, it's too strong to be necessary in stating that it's the "most effective" way. -
EIn practice, it is Remaining source text redacted.
Why choice E is not credited
Incorrect. The argument is about which of two methods is more productive, not what the most productive, so this answers is too extreme and out of scope.
What this tests
Discussion
-
A vs B 1 reply
Started by RachP