Logical reasoning PrepTest 124 · Section 2 · Question 1

Correct. Argument or Facts:
Facts

Question Type:
Paradox

Stimulus Summary:
Toxaphene levels are high in a lake despite it being banned decades ago.

Answer Anticipation:
For all Paradox questions, it's important to clearly define the paradox. Here, the unexplained phenomenon is that there's a lot of pesticide in Lake Laberge despite it being banned from anywhere in the immediate vicinity decades ago and isn't used anywhere close to the lake. What could explain that?

If they hadn't gone out of the way to note that it isn't used close by, then it might be explained by people breaking the law and banning a used substance. However, the stimulus specifically notes that it isn't used in the area, so anything about people breaking the law locally is a trap answer.

What could explain it is that toxaphene takes a long time to degrade in the environment. If the pesticide is persistent, then it might have stuck around for the decades between the last use in the area and the current day.

Answer Explanation:
This answer matches our anticipation—that pesticides can persist even after they're no longer used. If that's true, then it explains how the toxaphene levels are still high at Lake Laberge even though it hasn't been used in the area for decades.

Key Takeaway:
In Paradox questions, note when the stimulus specifically rules out a potential explanation. Here, one thing that could have resolved the paradox was if people still used the pesticide despite the ban. The stimulus notes that it isn't still used. That eliminates a potentially correct answer, and it instead makes any answer in that vein a trap answer. It wasn't given as one here, but it easily could have been, and often is in this question type.

Incorrect. Other pesticides being present doesn't explain the persistence of toxaphene. Without connecting other pesticides to preserving toxaphene, this answer is out of scope.

Incorrect. This makes the paradox worse. If toxic chemicals don't travel in the atmosphere, then that rules out one potential (albeit unlikely) source of the pesticides—those distant locales using it are releasing it into the atmosphere and it's traveling to Lake Laberge. By ruling out an explanation, this answer exacerbates the weirdness of the phenomenon.

Incorrect. Their opposition doesn't change the fact that toxaphene has been banned and isn't used in North America.

Incorrect. First, the stimulus notes that the levels of the pesticide in the lake are high, not that they are just detectable. Second, there's no indication that there are fish in Lake Laberge. Third, even ignoring those, that still doesn't answer how this stuff is still around after decades—just how it could be potentially detected.