Official Explanation
In a well-known karaoke club, a professional singer was hired to assist guests who had trouble staying in tune with the songs they were attempting to sing. On the first night, this caused discomfort to many of the guests who upon hearing their voices alongside that of the professional, suddenly lost confidence and felt embarrassed. On the second night, the number of singing guests who felt embarrassed by the professional's assistance was lower. Therefore, the club should not cease the employment of the professional singer, as in time the guests' discomfort will have diminished completely.
The author's conclusion relies on which of the following assumptions?(A) The popularity of a karaoke club does not depend on the standard of vocal capability displayed by the guests.
Incorrect.
To solve this Assumption question, first break down the argument. Sentences 1, 2, and 3 present factual information about events that actually occurred, so they are the premises of the argument. Sentence 4 uses the conclusion conjunction Therefore so we can be sure that it is the author's conclusion.
Now ask yourself: the author believes that the singer should not be fired because at some point the guests will stop being embarrassed. What assumption has the author made from the premises presented by the argument, to reach this conclusion?
The factors affecting the popularity of a karaoke club are irrelevant. Although it may seem logically connected to the argument, this answer choice presents new data instead of providing a reason for how the author reached the conclusion that he or she did.
(B) Employing a professional singer is not necessarily expensive.
Incorrect.
Since the topic of money is not mentioned in the argument, the costs involved in hiring a singer are irrelevant. Although it may seem logically connected to the argument, this answer choice presents new data instead of providing a reason for how the author reached the conclusion that he did.
(C) The suggestion to hire a professional singer was first made by the guests themselves.
Incorrect.
This answer choice presents a new premise about the employment of the singer. Although it may seem connected to the argument somehow, we are not interested in support for the conclusion; what we are looking for is the assumption, which should explain how the author drew the conclusion based on the existing premises.
(D) The guests' discomfort is caused by low self-esteem and a habit of comparing themselves with others.
Incorrect.
This answer choice presents a new premise about the psychology behind publicly performing. Although it may seem to be connected to the argument, we are not interested in support for or objections to the conclusion; what we are looking for is the assumption, which should explain how the author drew the conclusion based on the existing premises.
(E) Most of the guests visiting the club are returning customers.
The premises tell us that from one night to the next, the number of embarrassed guests decreased. However, if the guests were not the same, this difference was created simply by chance. To conclude that the guests' embarrassment is actually diminishing over time, the author must assume that most of the guests are the same people, who slowly feel less discomfort every time they sing at the club.