Task: Question Answering
Input (English): 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
Output (English): b