Civil Engineer: To ensure that a suspension bridge remains structurally sound under extreme wind conditions, the bridge's main cables must undergo ultrasonic tension testing. The inspection crew completed ultrasonic tension testing on the main cables of the Riverview Bridge last week. Thus, the Riverview Bridge is guaranteed to remain structurally sound during the upcoming severe storm.
Which of the following most accurately describes the flaw in the civil engineer's reasoning?
- Apresumes without providing justification that ultrasonic tension testing is the only available method for assessing structural stability
- Brejects the possibility that the inspection crew failed to execute the ultrasonic tension testing properly
- treats a requirement that is necessary for structural soundness as though it were sufficient to guarantee that soundnessAnswer
- Drelies on an unsubstantiated generalization that all suspension bridges face identical engineering risks during severe storms
- Econfuses a statement made in support of an intermediate conclusion with the main conclusion itself
Answer
The argument treats a condition that is necessary for structural soundness as though it were sufficient to guarantee that soundness.
The argument establishes that ultrasonic testing is required (necessary) for structural soundness under extreme winds. However, completing that test does not rule out other structural vulnerabilities (e.g., foundation failure, deck instability). By concluding that the bridge is guaranteed to remain sound solely because the necessary test was conducted, the author erroneously treats a necessary condition as sufficient.
Step-by-Step Solution
Key Concept
Necessary versus Sufficient Conditions (Conditional Reversal)
Estimated Time:1m 15s