Logical reasoning PrepTest 134 · Section 3 · Question 6

Incorrect. There's no discussion of the larger fish, so this answer is out of scope.

Incorrect. The Resident's conclusion is limited to discussing "this pond."

Incorrect. The conclusion is limited to discussing the effects of large amounts of algae on "smaller fish," so this answer is out of scope in discussing fish of different sizes.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
LR: Each time I've seen a lot of dead small fish, I've seen a lot of algae. Therefore, too much algae must kill small fish.

Answer Anticipation:
Two big issues in this stimulus!

First, the conclusion is causal, so we should check for a correlation/causation flaw. Here, the Resident's conclusion that algae is bad for small fish comes from seeing algae and dead small fish around the same time. That's a correlation, so there's a correlation/causation flaw present in this argument.

Second, the conclusion is based on the "few times" that the Resident has witnessed this correlation—hardly a scientific or statistically valid sample!

Either of these flaws could be raised in the correct answer, so let's stay flexible.

Answer Explanation:
This answer points out one reason that a correlation/causation jump is flawed—the correlation might highlight two effects of a third phenomenon that's the true cause. For instance, maybe some type of substance dumped into the pond causes both small fish death and algal blooms. Since this answer highlights the correlation/causation flaw, it's the correct answer.

Key Takeaway:
Don't be concerned if you spot two flaws in an Errors in Reasoning question! That just opens up two potential answer choices. It only becomes a problem if both flaws you believe to be present show up in the answers—and in that case, you're wrong about one of them.

Incorrect. The argument states that too much algae hurts smaller fish; that's compatible with too little algae also hurting them. Maybe they need to have just the right amount of algae.