Group 12 Question 56: The city legislature in Grand Hills...

(D) People who begin taking shorter showers are more likely to shower twice, rather than once a day.

So even if the residents reduce their shower time to 5 minutes, taking bath twice in a day defeats the purpose.

Official Explanation:

The city legislature in Grand Hills, in an attempt to address water shortages in the city, have mounted a publicity campaign to encourage residents to save water by keeping their showering time to about 5 minutes. According to the legislature’s estimates, this should result in the average household using between 10% and 20% less water each month.

Which of the following, if true, would most indicate a weakness in the city legislature’s efforts to address the water shortage?

(A) The amount of water used by businesses in Grand Hills far exceeds the amount used by people in their homes.
(B) Most people in Grand Hills claim that they spend between 5 and 10 minutes in the shower.
(C) A new plumbing system is now available that would reduce household water consumption by between 30% and 35%.
(D) People who begin taking shorter showers are more likely to shower twice, rather than once a day.
(E) A new report suggests that the savings estimate given by the legislature is substantially too high.

Question Type: Weaken
Boil It Down: A city attempting to address water shortages launched a campaign to limit showers to 5 minutes. 5-minute showers, based on estimates, should result in between 10% to 20% decrease in water usage per household.
Goal: Find the option that best weakens the argument that shortening showers to 5 minutes will decrease water usage.

Analysis:
As we do with all assumption family questions, we should plug this in and try to find an assumption:

Evidence: our publicity campaign tells people to only take 5-minute showers
Assumption: ?
Conclusion: We will save about 10% to 20% in water per household each month.

So, what is the prompt assuming? Well, lots of things. The prompt assumes that people will hear about the publicity campaign. It assumes that people will listen to it. It assumes that there is nothing else which will offset the five-minute showers. It assumes that people are taking longer than 5-minute showers. As you can see, it assumes a lot. To weaken the conclusion, we just need to poke a hole in one of the assumptions. For example, I’d be very happy with an answer choice that said, “In the history of Grand Hills, most publicity campaigns are unsuccessful and only a tiny minority of residents actually hear them and heed their warnings.” This would attack an assumption of the prompt, and therefore undermine the logic.

(A) The amount of water used by businesses in Grand Hills far exceeds the amount used by people in their homes.
I cannot blame anyone who fell for this trap answer. It is a very well written trap. If businesses use the majority of water, then how would water consumption reduce if people are taking shorter showers? You would be correct; but one word in the prompt makes this answer irrelevant: “Household.” The prompt says it will reduce water consumption by 10% to 20% per household. Businesses are not included in water consumption per household, so this answer is irrelevant.

(B) Most people in Grand Hills claim that they spend between 5 and 10 minutes in the shower.
I’m not sure how this weakens the conclusion? If all the people who spend 10 minutes reduce to 5 minutes, surely water consumption per household will decrease a bit? This answer does nothing to weaken our conclusion.

(C) A new plumbing system is now available that would reduce household water consumption by between 30% and 35%.
A classic fallacy of “XYZ does it better, therefore our solution is wrong.” Well, that’s not how it works. Just because there is something that does it better does not mean that suggesting 5-minute shower times will not have an impact on water consumption. What if the new plumbing system is prohibitively expensive? Solar panels, for example, are far better for the environment than typical electrical systems. However, solar panels also cost ~$20,000 more than less environmentally friendly systems. This answer is wrong.

(D) People who begin taking shorter showers are more likely to shower twice, rather than once a day.
I like this. It undermines our conclusion. Even if people take 5-minute showers, they start to shower twice a day rather than just once. Presumably, two 5-minute showers is just as bad as one 10-minute shower per day. This would weaken our conclusion that water consumption will go down after this mandate is in place.

(E) A new report suggests that the savings estimate given by the legislature is substantially too high.
Do we care about savings? We simply care about consumption of water. The city wants to do this to reduce water consumption per household. The evidence and conclusion are focused on saving water. This answer choice brings savings into it, which is not relevant for the conclusion we are trying to weaken. This answer is wrong.


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