Confusing CR

[ChandraXXX]

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?

A) Most of the 200 participants improved their emotional state and lowered their stress levels.

B) During each week of the experiment, the participants spent at least 2 hours less on their academic work as a result of concert attendance.

C) Listening to classical music for at least 2 hours per week improves the emotional well-being of the majority of young adults.

D) More than 6 participants attended at least 14 concerts during the course of the experiment.

E) At least some of the students participated in the study in order to gain free access to classical concerts.

SPOILER: OA is D.

I am not convinced with the OA. I am somehow inclined to C. Can anyone please shed some light on it please?

[bobby_in]

yeah.. really confusing..
none look good..

not even C, becoz only information about only people who attended most sessions of the 12 concertsis given.. we dont know whether they attended all or they attended just 2 & still figured as most attended..

if the number 14 in D were a collective number (for all the concerts attended by 6 participants), that looks good.

[sasen]

D seems to be the onli option which forms a true subset of the total hours and total concerts..rest of the options are subjectve to some extent except A which cant be confirmed from the passage.i agree the question was not simple

[ChandraXXX]

Thanks,
But can you please explain how to reach the number 14?

[madhur_ahuja]

This is mathematical question. I really doubt it can appear on GMAT.

Here is the solution. We need to consider the worst case scenario.

Since argument divides students into most , fewest watched. There could be at minimum 3 buckets. Most , Middle, Fewest.

In worst case:
Students in Fewest categories watched 1 concert per week.
Students in middle category watched 1 concert per week, but 2 concerts in last week.
Students in most category watched 1 concert for 10 weeks, but 2 concerts each in last 2 weeks.

Hence:
1. (Fewest category)20 students watched 1 per week =>12 concerts in 12 weeks
2. (Middle Category) 170 watched 11 in 11 weeks and 2 in last week => 11*1 + 1*2=13 concerts in 12 weeks.
3. (Most category) 10 students watched 10 in 10 weeks but 2 each in last 2 weeks=>10*1+2*2=14 concerts in 12 weeks.

From statement III, we can conclude that
10 students must have watched at least 14 concerts.

D. is right and changes 10 to 6 just to confuse the reader.


Most

[sasen]

All right here is how the number 14 is reached:
"all of the 10 students who attended the greatest number of concerts"
so the number of students attending concert has to > 6 (since 6 < 10)
i.e. 7 is the minimum # possible
now,coming to the # of concerts.....if these people were among the group attending "greatest number of concerts" thei have to attend atleast 2 since everi one has to attend atleast 1 concert.this makes 7 * 2 = 14 concerts...
hope that explains the math

[ChandraXXX]

Thanks Madhur, Sasen.

I got it now.

Yes, its kind of mathematical. Actually its a manhattan exam Q.

[abhishek_mumbai]

Great explanation, madhur.

[hrif]

I agree with madhur

[madhur_ahuja]

Thank you guys for the encouragement