Logical reasoning PrepTest 101 · Section 3 · Question 11

Incorrect. The last line tells us that it's ecologically safer to process cotton that isn't dyed vs. cotton that is, but that's not the same as comparing short- and long-fibered cotton.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Green/brown cotton:
(1) Previously not commercially viable
(2) Long-variety made that can be machine-spun
(3) Now commercially viable
(4) It doesn't have to be dyed, and the dye byproducts (ecologically damaging) don't need to be dealt with

Answer Anticipation:
This Must Be True question ends up relying on something that we see much more commonly in Reading Comprehension.

In RC, one of the most common patterns that the passage takes is to start with a current belief or situation, then bring up a change, and finally describe what that change has resulted in.

Here, the same pattern is followed. At first, there was green/brown cotton that wasn't commercially viable. Then, long-fibered varieties of these cotton fibers were created, and then they were commercially feasible.

In general, when a Must Be True stimulus presents a situation like this, the correct answer is a weak generalization (e.g., "Commercially unviable products can become viable as new technologies develop"), so let's head into the answers expecting that.

Answer Explanation:
The change that resulted in green and brown cotton "bec[oming]" commercially viable was that a long-fibered variety that could be spun by machine was "finally" bred. As such, we can infer that the non-machine-spun varieties must have been spun by hand, and were not commercially viable. This answer reflects the noted change in the stimulus, so this is the correct answer.

Key Takeaway:
A common pattern on the LSAT (though much more in RC than LR) is discussing a "status quo," a change, and then the results of that change. If you spot this pattern and identify those elements, you'll be in good shape to tackle the question.

Incorrect. There's no discussion of the ecological benefit of hand-spun vs. machine-spun cotton, just dyed vs. undyed cotton.

Incorrect. The stimulus doesn't discuss synthetic fibers, so this answer is out of scope.

Incorrect. While processing plans can avoid certain expenses when starting with green/brown cotton, there's no indication that the fibers themselves aren't more expensive, making up the difference. And even if the cost of producing a green/brown garment from these cottons is cheaper, there's no indication that the sellers would pass that on to consumers!