PrepTest 133

Incorrect. The stimulus notes that this is how the doubling of the speed of microchips has been accomplished, but it doesn't note that it's the only way to accomplish it.

Incorrect. If anything, the argument suggests that the cost did increase as the cost of at least one component kept doubling.

Incorrect. While the cost has doubled since the mid-1990s with each jump in computing speed, there's no indication that engineers haven't put in efforts to control costs. Maybe those costs would have been even higher without some cost-saving engineering!

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Several decades - Doubling microchip transistors doubled their speed
Since mid-90s - Doubling the speed doubled the cost

Answer Anticipation:
This stimulus has two important features to note.

First, the timeline. The first statement applies to "several decades," whereas the second applies only to the time period since the mid-90s. We need to make sure that the correct answer, if it brings in cost, limits itself to discussing the latter time period.

Second, the two premises have a shared term—doubling the speed. If doubling the transistors doubles the speed, and doubling the speed doubles the cost, then we can infer that doubling the transistors has been associated with doubling the cost.

Answer Explanation:
A doubling of transistors has led to a doubling of speed, and a doubling of speed has led to a doubling of cost. Therefore, we can conclude that a doubling of transistors has led to a doubling of cost, and this answer is supported.

Key Takeaway:
Pay attention to timelines when they're presented in any stimulus! Here, an incorrect answer could have easily tried to reframe (D) to be true at all times, and we don't have support for that in the stimulus.

Incorrect. Talking about what will happen in the future is almost never going to be supported in a Must Be True question, especially when it uses extreme language ("will ever be able to").