Bunuel
In response to a recent survey conducted by a newspaper in Quantos city, 70% of the respondents stated that they are very happy with the performance of the mayor and 20% stated that they are reasonably happy with the performance of the mayor. Only 10% of the respondents stated that they were unhappy with the performance of the mayor. So, it seems safe to conclude that the residents of Quantos City are in general happy with the mayor’s performance.
Which of the following options most strongly weakens the above argument?
(A) The mayor has been in the news a lot lately because of corruption charges that have been pressed against him.
(B) The primary readership of the newspaper that conducted the survey comprises the economically well to do people, a demographic that makes up only 20% of the population of Quantos City.
(C) The crime rate in Quantos City has not gone down during the term of the mayor.
(D) The mayor is against the abolition of property tax in Quantos City whereas most of the residents of the city are in favour of such a move.
(E) The survey is representative of the entire population of Quantos City.
Official Explanation
The ConclusionThe residents of Quantos City are in general happy with the mayor’s performance.
The EvidenceThe majority of respondents to a survey have expressed satisfaction with the mayor’s performance.
The AssumptionThe assumption is where the representativeness factor will come into play. What if this survey was conducted only amongst the economically well off residents? It is possible then that the poorer residents of Quantos City may actually be unhappy with the mayor’s performance, but their views haven’t been taken into consideration at all in this survey. So for the argument to hold true, the author of the argument has to assume that the survey mentioned in the argument is representative of the opinion of the entire population of Quantos city. B questions this assumption and should be the correct answer.
Let’s look at the other options as well for clarity.
(A) The point still stands that a majority of the respondents to the survey have said that they are happy with the mayor’s performance.
(B) The correct answer.(C) Same as A.
(D) Same as A. Why are people then saying that they are satisfied with the mayor’s performance? Maybe this is not such a big issue for the people then.
(E) This actually strengthens the argument by stating that the survey is absolutely correct.
In general, whenever you see the terms
survey, poll, research, study, etc., mentioned in the evidence of any argument, immediately question whether this survey/poll/research is representative of the larger population as a whole. This will always be the assumption in the argument.
Then if you have to strengthen the argument, you will have to show that the survey/poll/research is indeed representative of the larger population whereas if you have to weaken the argument you will have to show that the survey/poll/research may not be representative of the larger population.