Source: Official Guide for the GMAT 13th Ed. Critical Reasoning; #10

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# Which of the following would it be

Which of the following would it be most useful to know in determining whether switching to LED arrays would be likely to help minimize Traverton's yearly maintenance costs?

### 1 Explanation

1

Benjamin Ansell

Step 1: Identify the Question
*Evaluate the Argument

Step 2: Deconstruct the Argument
*Sentence 1 - Background [and so] Conclusion
Sentence 2 - Premise (supports conclusion)
Sentence 3 - Premise (supports conclusion)

Argument Logic - The author is comparing and contrasting two things.

Step 3: State the Goal
Find an answer that is most helpful in assessing whether switching from incandescent light bulbs to LED light bulbs would "minimize the city's average yearly expenditures on its traffic signal lights."

Step 4: Work from wrong to right
A: The life of the light bulb could impact the cost. If you are replacing bulbs everyday compared to 1x per year, that would be very expensive. (maybe)
B: This does not help us compare the two light bulbs the author is arguing about. This ignores the comparison argument logic used. (NOPE)
C: It doesn't matter which company sells the light bulbs. This ignores the comparison argument logic used. (NOPE)
D: Increasing the number of lights used does not change the maintenance/bulb cost. The argument says that it "cost no more to purchase" aka "it's the same price." Also, if they are installing new lights, there's no conversion cost. (Since the conversation costs are minimal, the different components needed for an initial install are likely similar. However, if the costs where to be significant, it could theoretically change the answer as to which bulb is cheaper in year 1, but the argument is stating "yearly" not an initial cost.) This ignores the comparison argument logic used. (NOPE)
E: Whether the current crews know how to change the bulbs does not impact the yearly rate. This ignores the comparison argument logic used. (NOPE)