In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: for a certain exam , a score of 60 was 2 standard deviations below mean and a score of 100 was 3 standard deviations above mean . what was the mean score for the exam ? 
Options: a ) 74 , b ) 76 , c ) 78 , d ) 80 , e ) 82
[A]: b


[Q]: Problem: if w is the product of the integers from 1 to 30 , inclusive , what is the greatest integer k for which 3 ^ k is a factor of w ? 
Options: a ) 10 , b ) 12 , c ) 14 , d ) 16 , e ) 18
[A]: c


[Q]: Problem: 15 years hence , rohan will be just 4 times as old as he was 15 years ago . how old is rohan at present ? 
Options: a ) 20 , b ) 25 , c ) 30 , d ) 35 , e ) 40
[A]:
b