Critical Reasoning: Conclusion Weakening Questions
Two years ago, the number of people involved in car accidents in Terribilia was 345. Last year, the number increased to 435 people. We can conclude that the number of people involved in car accidents is on an upward trend and the number will be even higher this year.
Which of the following, if true, most weakens the above conclusion?
Incorrect.
[[snippet]]This answer choice may strengthen the conclusion by showing another parameter related to car accidents, other than the number of people involved, in which there was also an increase from two years ago to last year. By supporting the idea of an upward trend, this answer choice supports the author's prediction. However, you were asked to weaken the conclusion.
Incorrect.
[[snippet]]If anything, this answer choice strengthens the conclusion. It does so by stating another negative aspect of the road safety situation, and therefore supports the idea that fewer accidents will be prevented. If fewer accidents are prevented, the author's prediction will be correct. However, we are trying to undermine that prediction.
Well done!
[[snippet]]This answer choice weakens the author's prediction by providing an alternative explanation to the rise in the number of people involved in car accidents: there was a specific accident in which many people were involved. As this event (a chain accident) only happened once in all of Terribilia's history, and since basing a conclusion on a single case is logically unsound, this answer choice weakens the argument's conclusion.
Incorrect.
[[snippet]]This answer choice neither weakens nor strengthens the conclusion. Since the conclusion deals with this year, information about plans being made for the next decade is irrelevant because these plans will not effect the number of accidents this year.
If we were told that the new roads will be completed this year, this answer choice could have been correct: it seems logical to assume that at least some car accidents are caused by badly maintained roads.
Incorrect.
[[snippet]]If anything, this answer choice indirectly strengthens the conclusion, but you are required to weaken it. Although not every person involved in a car accident is the car's driver, there has to be at least one driver in a car. The greater the number of people who have a driver's license is, the more potential drivers there are. The more potential drivers there are, the greater the potential number of people involved in car accidents is.