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: ( 51 + 52 + 53 + … … … + 100 ) is equal to : 
Options: a ) 2525 , b ) 2975 , c ) 3225 , d ) 3775 , e ) 3885
d

Problem: a batsman makes a score of 100 runs in the 11 th inning and thus increases his average by 5 . find his average after 11 th inning . 
Options: a ) 40 , b ) 50 , c ) 62 , d ) 45 , e ) 56
b

Problem: x is a positive integer less than 400 . when x is divided by 7 , the remainder is 1 ; when x is divided by 3 , the remainder is 2 . how many x are there ? 
Options: a ) 21 , b ) 22 , c ) 23 , d ) 24 , e ) 25

c