PrepTest 154

Incorrect. This is the converse of what we'd like to see. It diagrams as: IF good place, THEN well-maintained & reasonable prices. That doesn't tell us anything about how to determine if somewhere IS a good place to buy used workout machines. The contrapositive is IF NOT well-maintained OR NOT reasonable, THEN not good place. Also not useful.

Incorrect. We don't need to know which kind of machine is best to buy. We need to know what makes a particular place a good place to buy used machines.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen (Principle)

Stimulus Summary:
Gyms and fitness centers sometimes upgrade and sell off their old machines reasonably. They've seen heavy use, but are well-maintained and were built to handle a heavier workload than home fitness machines. So, gyms and fitness centers may be good places to buy used workout machines.

Answer Anticipation:
Notice the weakness of the conclusion here. To validate this conclusion, you only need to prove that it is possible for gyms and fitness centers to be good places to buy used workout equipment. So what needs to happen in order to do that? Well, it might be nice to have a definition of "good place to buy . . . " that proves gyms and fitness centers qualify. "Good place to buy . . . " is a term found only in the conclusion, which by definition makes the argument invalid. You can cross off any answer choices that don't at least include this term.

Answer Explanation:
Now this, we can use. It diagrams as IF well-maintained & reasonable prices, THEN good place to buy. That allows us to properly infer the conclusion that gyms and fitness centers can (when they are selling off old equipment, which isn't all the time) be a good place to buy.

Key Takeaway:
In this Strengthen question, the correct answer choice functions as a Sufficient Assumption. If that bothers you, just remember that if you are able to validate the argument completely (necessary for a correct answer on Strengthen with Sufficient Premise questions) then you've definitely strengthened it. Not all Strengthen answers are Sufficient Assumptions, but all Sufficient Assumptions will strengthen. The question types are closely related and may overlap.

Incorrect. This doesn't help with the conclusion. Even if this were true, it doesn't mean that gyms and fitness centers are a good place to buy. It could be true that there are no good places to buy used fitness machines.

Incorrect. Points for being true in the real world, but not what we're looking for. We're hoping to define what is a good place to buy, not what isn't.