Logical reasoning PrepTest 124 · Section 3 · Question 8

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
Bacteria + Household cleaning products = Poisonous vapors
Household cleaning products are found in landfills
Therefore - Making parks out of landfills harms human health

Answer Anticipation:
One important skill on the LSAT is seeing what terms in the premises connect to related ideas in the conclusion. For example, here the conclusion is about harming human health. In analyzing this argument, it's important to know that the argument is connecting the idea of poisonous vapors in the premises to the harm to human health in these answers.

With that established, we can see that the argument is saying that these landfills—which include household cleaning products—are releasing poisonous vapors after converted into parks. However, look at that equation we created. The household cleaning products are only part of the story—it must also be the case that the bacteria are present in the parks. There's no indication that those bacteria are!

It's possible that that bacteria only exists in closed spaces, or the landfills are treated in a way that kills all the bacteria. The argument is assuming the bacteria will be present in these ex-landfill parks, so let's find an answer stating that.

Answer Explanation:
This answer establishes that the other part of the "equation" that leads to poisonous gas is present in at least some of these parks. If there's no bacteria in any of the parks that were converted from landfills, then there's no poisonous vapors and thus no established threat to human health.

Key Takeaway:
One important skill in tackling LR questions that rely on analyzing the logic of the argument is tracking ideas even when terms shift a bit. Here, noting that the Environmentalist was talking about toxic vapors when she stated that something was harmful to human health in the conclusion was key to working through the logic. This can seem small, but failing to think comprehensively about an argument is an easy way to lose sight of the logic!

Incorrect. An answer highlighting how there aren't threats to human health probably won't be necessary for an argument that there are. When an argument states that something has a given effect, it doesn't rely on other things not having that effect.

Incorrect. Tempting! This answer connects vapors from household cleaning products to human health. However, there's a subtle shift here. The stimulus is about toxic vapors, which, by definition, will impact health. This answer is about all vapors from household cleaning products. As such, this answer isn't required for the argument to work, as it's possible that there are some benign vapors from household cleaning products, and that some vapors are harmful to health has already been established.

Incorrect. This answer weakens the argument by establishing that the threat highlighted by the Environmentalist could be prevented.

Incorrect. This answer is too broad in talking about any landfill, not just those converted to parks.