Wednesday's questions and sample explanations - #9

9. The mural in the executive dining room was painted more than 40 years ago. Since then, its exposure to extremes of heat and humidity has caused some of the once-vivid colors to fade. Fortunately, the painter’s notes included precise instructions for mixing pigments. Using these instructions and his leftover paints, skilled preservationists will be able to restore the mural to its original colors.

The conclusion logically depends on which one of the following assumptions?

1. The preservationists will be able to duplicate the muralist’s technique.
2. The wide variations in temperature and humidity typical of food-service areas make the executive dining room a poor location for a mural.
3. The artist foresaw that the colors would fade with time.
4. The paints left over from the mural’s creation have not themselves changed color.
5. At the time the mural was painted, temperature- and humidity-control technology was insufficient to prevent it from fading.

(D) is correct. This is a very narrowly-defined, precise argument: If the preservationists use the paints and instructions that the artist left behind, they can reproduce the painting's original colors. This cannot happen if the paints themselves have changed color since the artist used them originally. If the paints have changed color, then the colors they produce will be different.

(A) is incorrect because the argument is limited to the colors, not the painting's overall appearance. The goal is simply to restore the colors, not the painting's appearance. (A) might be correct if the artisans were trying to copy or reproduce the entire painting. But that is not the argument.

(B) is incorrect because, while it is probably true, it's irrelevant to the argument. The fact that this is not a good place to hang a painting has no effect on whether the original colors can be restored using the original paints and artist's instructions.

(C) is incorrect even though it might be a valid inference. It could be inferred that if the artist had not anticipated that the colors would fade, he would not have left the paints and instructions behind. However, we have not been asked for an inference. In addition, and more importantly, the stimulus tells us that he DID leave the paints and instructions behind. It doesn't matter why he did it, or whether he would have done it under different circumstances. He did it.

(E) is incorrect because, like (B), it is probably true but irrelevant to the argument. Whether the fading could have been prevented in the past has no effect on whether the colors can be restored now.