New types of washing machines designed to consume less energy also extract less water from laundry during their final...

Brendan on July 1, 2017

Writing another comment in this thread since the original post did not ask me whether or not I wanted to alert the instructor which seemed odd. Not sure if this was brought to your attention yet. Thank you!

Mehran on July 7, 2017

@Brendan let's take a look at the reasoning the stimulus first.

New washing machines designed to consume less energy extract less water but wetter laundry requires more energy to dry.

Thus, these new washing machines could result in an overall increase in the energy needed to wash and dry a load of laundry.

So the idea here is that these new washing machines could be counterproductive, i.e. use more energy when designed to consume less energy.

There is nothing counterproductive about (A).

Compare that to (D):

Pine is less expensive than cedar but more susceptible to rot, so outdoor furniture made from pine must be painted with more expensive paint.

Therefore, building outdoor furniture with pine rather than cedar could increase the total cost of building and painting the furniture.

This is the exact same pattern of reasoning as we saw in the stimulus so (D) would be the correct answer.

Hope that helps! Please let us know if you have any other questions.

KimJongUn on November 13, 2018

How do we know total cost of building is more expensive on D? What's wrong with C?

Mehran on November 13, 2018

Hi @KimJongUn, thanks for your post. Answer choice (D) gives you enough information to understand that the cost of *building and painting* outdoor furniture from pine (rather than from cedar) could be more expensive. Why? Even though pine is less expensive than cedar, pine wood is more susceptible to rot (than cedar) and so it has to be painted with more expensive paint. This means that the total cost of *building and painting* outdoor furniture made of pine is more than cedar.

As explained above on this thread, the stimulus thus presents you with information that indicates that "energy efficient" washing machines actually end up increasing the total amount of energy needed to wash and dry a load of laundry, and answer choice (D) presents you with information that indicates that a cheaper kind of wood can, if used for outdoor furniture, end up costing more (for building and painting) than a more expensive kind of wood. These are counterproductive outcomes (opposite from what is presumably intended by consumers who are making these selections).

Unlike the stimulus and the correct answer choice (D), answer choice (C) does not have a parallel counterproductive quality. Rather, it presents a straightforward transitive argument: the more people working in the library reading room (MPW), the noisier it becomes (N). The noisier the working environment, the less efficiently people work (LEW). Therefore, when many people are working in the reading room, those people are working less efficiently. MPW ==> N ==> LEW. This is not parallel to the reasoning in the stimulus.

Hope this helps. Please let us know if you have any additional questions.