QUESTION TEXT: Each new car in the lot at…
QUESTION TYPE: Parallel Reasoning
CONCLUSION: Any car in Rollway’s lot that costs between $5,000 and $18,000 is a used car that is less than 10 years old.
REASONING: New cars cost more than $18,000. So any car that costs less than $18,000 is used.
Old cars (10+ years) cost less than $5,000. So any car that costs more than $5,000 is recent (less than 10 years old).
These principles are combined to form the conclusion: any car that costs more than $5,000 but less than $18,000 is used and recent.
ANALYSIS: This argument uses two conditional statements and their contrapositives.
Old —> less than $5,000
Not less than $5,000 —> not old (recent)
New —> more than $18,000
Less than 18,000 —> Not new (used)
Don’t make an incorrect negation mistake here! Something like “all recent cars cost more than $5,000” is an error. We only know that no old cars cost more than $5,000.
The correct answer will use a pattern like this:
A —> B
B —> A
C —> D
D —> C
B + D —> A + C
All of the answers write in terms of apartments. I’ve rephrased them in terms of cars from the original. Hopefully this helps clarify the structure.
___________
- This does not follow the pattern. This is more like if the original argument was “Cars older than 5 years cost more than $5,000. Cars more recent than 5 years cost less than $5,000. Thus, cars that are 5 years old cost exactly $5,000”.
- This argument is valid, but doesn’t match our pattern. This is like “Cars less than 5 years old cost $5,000 or $6,000. No car more than 5 years old costs more than $4,000. Thus, any car that costs $6,000 is less than 5 years old”. It works as an argument, but the question isn’t asking us which one is not flawed.
- CORRECT. This answer matches our pattern of reasoning.
All apartments on the 5th floor or above have 3 or more bedrooms. So any apartment with less than 3 bedrooms is below the 5th floor.
All apartments on the 3rd floor or below have 1 bedroom. So any apartment with more than one bedroom is above the 3rd floor.
Thus, any apartment with less than 3 bedrooms but more than 1 bedroom must be both below the 5th floor and above the 3rd floor.
This answer is tricky because it rephrases the concepts from the stimulus – you may have been looking for a range of values to parallel the “between $5,000 and $18,000” idea from the stimulus. But we do have a range here, really! The equivalent is “between 1 and 3 bedrooms”, which the answer rephrases as 2 bedrooms.
- This does not match our pattern. This is like “No car older than 5 years costs more than $5,000. But only $6,000 cars have heating. So if a car has heating, it is not older than 5 years”. It makes sense, but doesn’t match.
- This doesn’t match our pattern. This is like “Any car less than 5 years old costs more than $5,000. The lot has no cars that are 5 years old or more. So, if there is a car on the lot, it costs more than $5,000”. Again, this argument makes sense but it doesn’t match.
Free Logical Reasoning lesson
Get a free sample of the Logical Reasoning Mastery Seminar. Learn tips for solving LR questions
Leave a Reply