Bunuel
In an interview that appeared in a weekly plumbing magazine, the chairperson of the Plumbing Association stated that plumbers are called 45% more on Fridays than on any other day of the week. The chairperson claimed that, though unexplained, it seems pipes are 45% more likely to burst on Fridays.
Which of the following, if true, would most seriously weaken the chairperson's claim that pipes are 45% more likely to burst on Fridays?
(A) Not only plumbers but also electricians are requested to fix appliances on Fridays more than on any other day of the week.
(B) People are more concerned about their houses being intact before the weekend than on any other time during the week.
(C) A comprehensive survey of 504 households throughout the United States clearly shows that plumbers are called 45% less frequently on Sundays than on any other day of the week.
(D) Plumbers charge twenty percent more for house calls made on Friday.
(E) There is an undeniable correlation between the strength of the metal used for pipes and the anti-oxidizing coating it is painted with prior to installation.
OFFICIAL EXPLANATION
In an interview that appeared in a weekly plumbing magazine, the chairperson of the Plumbing Association stated that plumbers are called 45% more on Fridays than on any other day of the week. The chairperson claimed that, though unexplained, it seems pipes are 45% more likely to burst on Fridays.
Which of the following, if true, would most seriously weaken the chairperson's claim that pipes are 45% more likely to burst on Fridays?(A) Not only plumbers but also electricians are requested to fix appliances on Fridays more than on any other day of the week.
Incorrect.
To solve this Conclusion Weakening question, first break down the argument. The first sentence is a premise providing factual data. The chairperson makes a judgment based on that information - this is the conclusion:
Premise A: plumbers are called 45% more on Fridays than on any other day of the week
=
Chairperson's claim: pipes are more likely to burst on Fridays
Possible assumption: there is no factor other than the likelihood of pipes to burst that affects how often plumbers are called out
Weakening Data: ?
You are required to find data that weakens the conclusion that pipes are more likely to burst on Fridays. The correct answer could be one that exposes the argument's assumption.
The fact that electricians are also called 45% more on Fridays is irrelevant to the conclusion. The conclusion claims that pipes burst on Fridays more than other weekdays so to weaken this claim we will most probably not have to include any reference to electricians.(B) People are more concerned about their houses being intact before the weekend than on any other time during the week.
This answer choice weakens the chairperson's claim by attacking its underlying assumption and providing an alternate explanation to why plumbers are called more often on Fridays. If people are more concerned about their houses being intact around Friday, they are likely to call maintenance professionals more frequently during that time.(C) A comprehensive survey of 504 households throughout the United States clearly shows that plumbers are called 45% less frequently on Sundays than on any other day of the week.
Incorrect.
This answer choice neither weakens nor strengthens the claim that pipes burst on Fridays more than other weekdays. The fact that Sundays are the quietest days for plumbers is irrelevant since it has nothing to do with the conclusion of the argument which only deals with Fridays.(D) Plumbers charge twenty percent more for house calls made on Friday.
Incorrect.
The fact that plumbers charge 20% more on Fridays could perhaps explain why they would be called less often. However, in this argument, the premise deals with a situation where plumbers are called more often. Therefore, this answer choice fails to discredit the chairperson's claim.(E) There is an undeniable correlation between the strength of the metal used for pipes and the anti-oxidizing coating it is painted with prior to installation.
Incorrect.
Though there is an undeniable connection between the material a pipe is made of and its chances of bursting, this information isn't connected in any way with the conclusion that pipes burst more on Fridays, and is thus irrelevant. Remember, you're looking for a statement that weakens the chairperson's claim about pipes bursting on Fridays.