A recent research study of undergraduate students analyzed the effects of music on human emotions. Each of the 200 participants attended at least 1 two-hour concert of classical music per week over the course of 12 weeks of their spring semester. At the end of the experiment, all of the students filled out a questionnaire assessing their emotional state. Based on the results of the questionnaires, all of the 10 students who attended the greatest number of concerts reported lower stress levels and higher satisfaction with their lives. Also, most of the 20 students who attended the
fewest number of concerts reported below-average levels of emotional comfort.
Which of the following must be true based on the evidence presented above?
Most of the 200 participants improved their emotional state and lowered their stress levels.
During each week of the experiment, the participants spent at least 2 hours less on their academic work as a result of concert attendance.
Listening to classical music for at least 2 hours per week improves the emotional well-being of the majority of young adults.
More than 6 participants attended at least 14 concerts during the course of the experiment.
At least some of the students participated in the study in order to gain free access to classical concerts.
Please post answers with explainations.
I personally think this question would never show up on the GMAT, but here is my take on it.
The key is to recognize that the passage refers to 3 groups of people who attended different numbers of concerts - the 'greatest' group of 10, the 'not mentioned - middle' group of 170, and the 'fewest' group of 20.
Combine this with the fact that the students at minimum have to attend 12 concerts (1 per week) we get =>
Fewest group => at least 12 concerts
middle group => at least 13 concerts
greatest group => at least 14 concerts
If we know the greatest group have attended at least 14 concerts, then we know D)