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'.

[EX Q]: Problem: when 1 / 20 % of 4,000 is subtracted from 1 / 10 of 4,000 , the difference is 
Options: a ) 50 , b ) 200 , c ) 380 , d ) 398 , e ) 400
[EX A]: d

[EX Q]: Problem: the average of the marks of 30 students in a class is 45 . if the marks of each student are doubled , find the new average ? 
Options: a ) 85 , b ) 77 , c ) 33 , d ) 90 , e ) 75
[EX A]: d

[EX Q]: Problem: the average runs scored by a batsman in 20 matches is 40 . in the next 10 matches the batsman scored an average of 30 runs . find his average in all the 30 matches ? 
Options: a ) 31 , b ) 36.67 , c ) 88 , d ) 13 , e ) 12
[EX A]:
b