PrepTest 133, Section 1, Question 9
Computer scientist: For several decades, the number of(45 more words not shown)
Which one of the following(9 more words not shown)
- AThe only effective(18 more words not shown)
- BFrom the mid-1990s(27 more words not shown)
- CFor the last(25 more words not shown)
- DFrom the mid-1990s(25 more words not shown)
- EIt is unlikely(21 more words not shown)
Reading the argument
The chips got faster, but the improvement came with a larger production bill.
Follow the two connections. Over several decades, the number of transistors doubled about every eighteen months, and the computing speed doubled with it. Then we're given a narrower period—from the mid-1990s into the next decade—when each doubling of speed came with a doubling of production cost.
What we’re looking for
Put those together for that specified period: twice the transistors went along with twice the speed and twice the production cost. That's the kind of inference the question invites. We don't need to predict the next technological breakthrough or decide what a store charged for a computer. Stay with the relationships the scientist actually describes.
Working the answers
- A
Adding transistors is a way to increase speed. Where does the passage say it is the only effective way? Perhaps better materials or some different design could also speed up a chip. Those are possibilities the passage doesn't rule out. A turns one successful method into the sole possible method.
- B
A chip's production cost isn't the retail price of a whole computer. If chips make up only a small portion of a computer's cost, doubling that portion might have a small effect. A seller might also change its profit margin or absorb the increase. But we don't know any of those things happened. We therefore can't conclude that there was little or no retail increase, any more than we could conclude that retail prices doubled.
- C
We know what happened to production costs, not how hard engineers tried to control them. Perhaps the engineers worked very hard to keep costs down and still couldn't prevent the increase. An unsuccessful attempt is still an attempt. C wrongly treats the outcome as evidence that no effort was made.
- DCorrect
During the stated period, doubling transistors accompanied doubling speed, and doubling speed accompanied doubling production cost. D connects the first and last pieces. 'Fabricating' means making the chips, so it restates the cost of producing them. It doesn't add a new claim about retail prices, motives, or the future.
- E
Ever is far more than this historical account establishes. Engineers might eventually find a way to increase speed without increasing production cost. The fact that improvements and higher costs went together during the period discussed doesn't show that they must remain linked indefinitely.
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