Logical reasoning PrepTest 155 · Section 1 · Question 1

This doesn't damage the argument at all. If you accept that killing more bugs = better, then it doesn't matter how close the competitors are to killing as many species as Omnicide. Omnicide still kills more bugs, so it is still better and the argument stands.

Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Stimulus Summary:
There's an ominously named insecticide (bug spray) called Omnicide that kills way more types of insects than any other bug spray. So that must be the best bug spray for your garden, right? The author adds a little extra premise about gardeners who can't tell what kind of bug is eating their plants, but the basic situation here is, "kills more species of bugs" = "better."

Strategy Overview:

1. Argument or facts? Always argument, so identify premises and conclusions of argument
2. Anticipate why the premises are not enough to show that the conclusion is true
   1. Causal argument? Look for answer choice that:
      1. Shows possible alternate cause
      2. Shows cause without effect
      3. Shows effect without cause
      4. Shows the cause and effect are reversed
   2. If not causal argument, anticipate ways to worsen problem with argument
3. Use anticipations to select the answer choice that, if true, would weaken argument

Answer Anticipation:

Our ultimate goal is to find the answer choice that weakens the argument. However, it's much easier to do that if we first break down the argument and identify its flaws. Then, we'll just find the answer choice that exploits that flaw, thereby weakening the argument.

Experienced flaw-finders will latch onto very bold assertions made in arguments' conclusions. A claim can be bold for many different reasons (such as the degree of certainty, universality, or exclusivity the claim expresses). But superlative claims — like saying Omnicide is "the best" bug spray for home gardeners here — are among the boldest and most challenging to support.

And indeed, this advertisement's main flaw is related to the claim that Omnicide is "the best" for home gardeners. The ad supports this rash claim by stating that Omnicide kills more bugs than any other bug spray. But is killing the most bugs possible actually what gardeners look for in a bug spray? Nothing in the stimulus specified that Omnicide kills more harmful insects than its competitors. Perhaps killing the most bugs results in killing all the beneficial bugs in addition to the harmful ones. (#SavetheBees.)

So we should look for an answer choice that exploits this flaw by showing any potential downside to Omnicide — like killing beneficial bugs — that make it less than the best bug spray for home gardeners.

Answer Explanation:
This is what we anticipated: a reason why a bug spray that kills more species might not be the best bug spray for home gardeners. If Omnicide kills most beneficial species, then an alternative product that leaves beneficial insects alone would probably be better than Omnicide.

Key Takeaway:
In Strengthen questions, we sometimes look to bridge a logical gap. In Weaken questions, the correct answer choice will often worsen or illuminate a gap in the reasoning found in the stimulus. Either way, paying attention to where the reasoning has made an unsupported leap is critical on these questions.

The advertisement never said Omnicide alone would ensure that plants are healthy! They just said it's the best bug spray. This doesn't weaken the argument, because the ad never claimed Omnicide was the only home gardeners needed to keep their plants healthy and hale.

Omnicide's profit margins might explain the company's motivation for promoting Omnicide through an ad, but a person (or corporation) can be both selfish and correct. If the ad's claims are accurate (and there are no downsides to killing the most insect species), it wouldn't matter that the claims are self-serving. So this doesn't weaken the argument.

(E) Like (C), this answer choice attempts to attack the argument by pointing out that Omnicide doesn't do something the ad never claimed Omnicide could do. Even if Omnicide can't kill weeds or mammals, its bug-killing prowess could still make it the best insecticide for home gardeners. After all, the purpose of a bug spray is to simply eradicate harmful bugs, not any threat to a plant's growth.