Logical reasoning PrepTest 136 · Section 2 · Question 10

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
Decrease size of CPU without decreasing sophistication → Faster CPU
not Decrease size of CPU without decreasing sophistication
Therefore - Currently, not Faster CPU

Answer Anticipation:
We framed this stimulus around conditional language, but there wasn't a need to do so. However, if you notice that a term is repeated and negated, you can frame it this way to drive home the flaw—a version of an illegal negation.

The argument establishes that one way to make a CPU faster is to make it smaller without decreasing the sophistication of it. However, it then establishes that it's not possible to do so, concluding that CPUs won't currently get faster.

An illegal negation assumes that the given sufficient condition is the only sufficient condition, ignoring other potential ones. Here, the stimulus never establishes that the method outlined is the only way to increase CPU speed. So the argument is relying on there being no other method of achieving that goal, and we should look for an answer stating that.

Answer Explanation:
This answer establishes that the method of increasing speed outlined in the stimulus is the only method to do so. If there are others, the argument falls apart, so this is the correct answer.

Key Takeaway:
Even if there isn't conditional language in an argument, if you see a term or concept repeated and negated, you should start to think about illegal negations. Even if you don't view it through that direct lens, thinking about alternative routes to the same destination will get you thinking about the flaw in the argument.

Incorrect. The argument relies on the inability to make a smaller, equally sophisticated computer chip, so it doesn't matter if it's impossible to make them smaller even if they are made less sophisticated.

Incorrect. The argument would still work if a smaller, less sophisticated chip is just as fast as current chips—it only relies on those chips not having the potential to be faster.

Incorrect. The beliefs of the computer manufacturers doesn't determine the physics of computer chips, so this answer is incorrect. Picking it would see you committing a perception to reality jump which we know is a common error!

Incorrect. If anything, this answer establishes an alternative means of speeding up chips without shrinking them (increasing their sophistication), which would cut against the argument.