Logical reasoning PrepTest 132 · Section 4 · Question 10

Incorrect. This answer doesn't describe a flaw—it describes the contrapositive! Since the contrapositive is a valid inference from a conditional statement, this answer could never be correct.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Europa most likely has liquid water.
Life evolves → Liquid water
Therefore: Life has likely evolved on Europa

Answer Anticipation:
The stimulus establishes a conditional rule for life evolving somewhere, but it establishes a necessary condition for life to evolve ("only in"), not a sufficient condition. The Journalist then tries to apply this conditional to Europa concluding that because Europa likely meets the necessary condition for life evolving, that life has evolved there. In other words, it treats a necessary condition for life as if it were sufficient for life to evolve. That's an illegal reversal, so let's find that answer.

Answer Explanation:
While this answer isn't phrased in a traditional illegal reversal manner, it still gets at the same flaw. Liquid water is necessary for life to evolve, but there could be other things needed, as well—in other words, liquid water by itself might not be enough for life to develop. This answer highlights the flaw in the Journalist's argument, so it's the correct answer.

Key Takeaway:
Errors in Reasoning questions frequently feature conditional logic flaws, so if you see conditional keywords in this question type, start diagramming and see if the argument illegally reverses or negates the logic.

Incorrect. The argument always talks about life evolving on Europa, not being present there, so this term shift doesn't exist in the argument.

Incorrect. This possibility doesn't undermine the argument, so overlooking it isn't a flaw. The argument only cares about life on Europa being likely because water is present, so if there's another type of lifeform that potentially developed there outside of where the water exists, all the better for the argument—after all, the conclusion is that life evolved on Europa, not that it evolved in the liquid water!

Incorrect. The argument does state that the data "strongly suggest" there's liquid water, so it does consider the possibility that something else accounts for that data. This level of uncertainty is reflected in the conclusion, which states that it's "likely" some life has evolved on Europa.