QUESTION TEXT: Most auto mechanics have extensive experience. Furthermore,…
QUESTION TYPE: Flawed Parallel Reasoning
CONCLUSION: Most car mechanics know how electronic circuits work.
REASONING: Most experienced mechanics know how electronic circuits work. And most car mechanics are experienced.
ANALYSIS: There are other types of mechanics, besides car mechanics. Maybe the mechanics who understand electronic circuits are those who work on tanks, submarines, airplanes, etc….machines that have electronic circuits.
Abstractly, the flaw is that even if something is true for most people in a group, it doesn’t have to be true for most people in a subset of that group. For example, suppose most pets are dogs. That doesn’t mean that most pets that live in fish tanks are dogs. So look for an answer that talks about most people within a larger group.
- This is a good argument. Traffic ➞ high gas price ➞ complaints.
- This is a bad argument. The most common species could account for, say, 10% of the total birds in the area. So even when that species leaves, 90% of the birds stay. But this is not the same flaw as in the stimulus.
- This is not quite a good argument. It hasn’t told us that drivers who want to drive fast do buy sports cars. Maybe drivers who want to go fast only buy trucks. But this is not the “most” flaw from the stimulus.
- Why would nature photographers find it especially boring to take pictures of famous people? They might prefer that to taking pictures of random people in a studio. But this is not the same flaw.
- CORRECT. This repeats the flaw. Why would a snow-removal business hire more people in the summer? Just because most people that run lawn care businesses do, doesn’t mean that most companies within a sub-group (snow-care) also hire in summer. Use common sense; snow-removal companies lose business when the snow goes away. Whereas companies that only do lawn care will hire in the summer.
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Sorry to say that your reasoning for answering the correct answer E is incorrect. My family owns one of the largest landscaping/snow removal companies in the nation. and they do snow removal in the winter. They hire plenty of subcontractors for removing snow during the summer.
I’m not gonna tell you how to phrase your answers but the one you gave is clearly wrong.
TutorLucas (LSAT Hacks) says
The gist of the explanation for (E) is that the answer choice is drawing a conclusion about most members of a sub-group based on a fact about most members of the group to which that sub-group belongs. This matches the flaw type in the stimulus, so I’d argue there isn’t a significant issue with the explanation here.
However, I do agree that we can’t automatically make the assumption that snow-removal companies don’t hire additional workers in the summer.
Just want to say that I solved this problem by using this formula;
1 most 2
2 most 3
Thus, 1 most 3
Would this be a correct way to solve this type of problem?
FounderGraeme Blake says
Yes, that’s correct. Preptest 64 was one of my earlier sets of explanations, looks like I wasn’t as methodical with doing most diagrams back then.
Though it’s important to know *why* you can’t combine most statements. For anyone reading this who doesn’t know, the explanation above covers that.
answer choice D isn’t consistent with this framework though…
A most B
B most C
thus A most C
answer choice D:
A most B
X most C
thus A most C
answer choice D introduces a new variable – companies that run lawn care services (this could be an entirely different group, one that is not a subset of A at all, unlike the main argument, in which mechanics with extensive experience are ALL a subset of the original group of mechanics). if it was to be directly parallel to the main argument, wouldn’t have to say “most *snow-removal companies* that run lawn-care services during the summer hire additional workers in the summer?
advice is appreciate. thanks