PrepTest 131

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Argument Evaluation

Stimulus Summary:
The accident was caused by either Driver 1 changing lanes without signaling or Driver 2 speeding, either of which would create liability. Driver 1 changed lanes without signaling, so Driver 2 isn't liable.

Answer Anticipation:
The stimulus establishes that liability is created by either changing lanes without signaling or speeding. It then establishes that there was liability for Driver 1. However, that's not the conclusion—the conclusion is that Driver 2 isn't liable.

To reach that conclusion, we'd need to know that he wasn't speeding or that only one person can be liable for an accident. As is, it's possible that he was also liable because he was speeding, running into someone changing lanes without signaling.

Answer Explanation:
An answer to this question will let us know if Driver 2 was also liable. If he was speeding, then he was; if not, then he wasn't. In helping us to know whether the conclusion holds, this answer helps us analyze the logic of the argument.

Key Takeaway:
When an argument rules out one thing because another is present, it's assuming the two things are mutually exclusive. While some things are mutually exclusive as a matter of definitions/logic (e.g., a single item can't be both heavy and not heavy), most mutually exclusive relationships will need to be explicitly established in the stimulus. Here, the author never establishes that both drivers can't be liable, so using the liability of one to disprove the liability of another is a flaw.

Incorrect. The stimulus establishes that liability is created when someone changes lanes without signaling—their awareness of the turn signal being on or off doesn't factor in.

Incorrect. Other drivers being involved wouldn't affect whether Driver 2 was liable—that determination comes down to whether he was speeding or not.

Incorrect. This answer would, at best, help to determine whether Driver 1 was liable, not whether Driver 2 wasn't. Since the argument never establishes that only one person can be liable, the two determinations are independent of each other.

Incorrect. There's no discussion of other drivers being aware of the turn signal being related to liability, so this answer is out of scope.