If a factory emits pollutants above a certain level, it must install an advanced filtration system.
Therefore, if a factory has not installed such a system, it must be emitting pollutants below the required level.
This reasoning is flawed because it assumes that the only reason a factory would not install an advanced filtration system is if it is emitting pollutants below the required level. However, there could be other reasons why a factory hasn't installed the system (e.g., non-compliance, evasion of regulations, lack of enforcement).
The flaw here is a mistaken contrapositive, or assuming that the absence of an action (installing a filtration system) implies the absence of a condition (emitting pollutants above the required level).
Similar Flaws in Answer Choices:
A. Any animal classified as a reptile must be cold-blooded, so if an animal is not cold-blooded, it cannot be classified as a reptile.
This is valid reasoning. It correctly applies the contrapositive.
B. All licensed drivers must pass a driving test, and since Jorge has passed a driving test, he must be a licensed driver.
This is flawed but not in the same way. Passing a driving test is a necessary but not sufficient condition for being a licensed driver. There could be other requirements.
C. A person who is an elected official must reside in the district they represent, so anyone who does not reside in a particular district cannot be an elected official there.
This is valid reasoning. It correctly applies the contrapositive.
D. Every person entering the country must go through customs; therefore, the increase in the number of customs agents will necessarily lead to a decrease in the number of people entering the country.
This is flawed reasoning, but it’s not the same type of flaw. It assumes causation between two unrelated events.
E. All professional athletes must undergo regular drug testing; hence, if someone has not undergone drug testing, they must not be a professional athlete.
This exhibits the same flaw as the original argument. It assumes that the only reason someone wouldn't undergo drug testing is that they are not a professional athlete, ignoring other possible reasons for not undergoing testing.
Correct Answer:E