Railroad spokesperson: Of course it is a difficult task to maintain quality of service at the same time that the amou...

Ryan on September 28, 2019

Why is B correct? Why is C incorrect?


1 Reply

Irina on September 29, 2019


This is a necessary assumption question - one way to approach this question is to negate each of the answer choices and see if the answer choice makes an argument fall apart when negated. The argument tells us that the number of passengers have increased over the years despite subsidy reductions, and concludes that the quality of service must have been satisfactory. The argument assumes the increase in number of passengers to mean that passengers are satisfied with the service.

Let's look at (B) and (C):

(B) Some people refuse to travel by train if they are dissatisfied with the quality of service.

The opposite of (B) would be none of the people refuse to travel by train if they are dissatisfied, meaning that there is no relationship between one's choice to travel by train and the satisfaction with the service. Even if they are dissatisfied, they still take the train because that is their only transportation option or for any similar reason. If this were true, the argument would no longer make sense because the ridership numbers are not reflective of the quality of service, hence we could not conclude that the service levels are still satisfactory. Thus (B) is a necessary assumption, at least some people refuse to travel by train when they are dissatisfied by the quality of service.

(C) The quality of service must have improved despite subsidy reduction.

The argument merely concludes that the quality of service has been satisfactory, or in other words acceptable. It is difficult to quantity what "satisfactory" means, it could be that the quality went up, stayed the same, or went down but it is still satisfactory to the passengers. Since we are not required to assume that the service must have improved to conclude that it is still satisfactory, this is not a necessary assumption for the argument to be valid.

Let me know if this makes sense and if you have any further questions.