Logical reasoning PrepTest 125 · Section 2 · Question 6

Incorrect. The argument discusses writing paper, which can be manufactured from recycled paper. The conclusion is also predicated on recycled paper replacing other writing paper. As such, this answer is out of scope.

Incorrect. The argument never discusses the environmental impact, or even whether using more fillers is a good or bad thing, so this answer is out of scope.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
Paper is naturally gray, but manufacturers use fillers to make it white. Recycled paper needs more filler to turn white than other paper. Therefore, without changes to this process, if more paper is recycled, more fillers will be needed.

Answer Anticipation:
The conclusion here is interesting in that it is double qualified. It is based on:
(1) No changes being made to the paper-whitening process
(2) A shift towards recycled paper
We're used to seeing a single qualification on a conclusion, but not two! This mainly serves to invalidate answers. For instance, without them, the correct answer could state that the argument assumes there won't be a more efficient use of fillers, or that that there won't be the development of non-filler based whitening techniques, or that recycled paper will replace other types of paper. With the qualifications on the conclusion, those are no longer potential answers.

So what is left for the argument to assume? Well, let's focus on what the conclusion states—that paper manufacturers will have to use more fillers. Why? Because those fillers make the paper white.

But that assumes that recycled paper will continue to maintain that color. If gray paper becomes acceptable (or even trendy!), then more fillers won't need to be used. Therefore, the argument assumes that paper manufacturers will continue to make paper that looks white instead of gray.

Answer Explanation:
This answer highlights another possibility other than manufacturers using more filler—gray writing paper starts to be sold. If grayish writing paper does become a universally acceptable alternative to white writing paper, then manufacturers might cut the fillers and sell the gray paper, invalidating the conclusion.

Key Takeaway:
Always note qualifications on conclusions when they show up! They will frequently serve to eliminate potential answers, which does two things. First, it narrows what elements of the stimulus you can anticipate in the correct answer. Second, it allows you to identify elements that will show up in trap answers so you can quickly eliminate them.

Incorrect. The argument doesn't require that there's a limit to how much filler can be added to change the color of paper. If anything, an answer that limits how much filler could be meaningfully used cuts against a conclusion about an increase in the use of filler.

Incorrect. While an increase in the amount of writing paper would suggest that more filler would be used, the conclusion is based on the amount of recycled paper increasing, which could call for an increase in filler without there needing to be an increase in total paper manufactured.