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'.

Problem: find value for x from below equation ? x + 1 = 4 
Options: a ) - 5 , b ) - 4 , c ) 4 , d ) 3 , e ) 2
d

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
b

Problem: 4 , 12 , 48 , 240 , ( . . . ) 
Options: a ) 1440 , b ) 10080 , c ) 6200 , d ) 10020 , e ) 12500

a