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: 49 ã — 49 ã — 49 ã — 49 x 49 = 7 ? 
Options: a ) 4 , b ) 7 , c ) 8 , d ) 10 , e ) none of these
[EX A]: d

[EX Q]: Problem: the mean of 40 observations was 100 . it was found later that an observation 50 was wrongly taken as 75 the corrected new mean is 
Options: a ) 125.8 , b ) 102.8 , c ) 99.375 , d ) 100.52 , e ) 122
[EX A]: c

[EX Q]: Problem: . 009 / ? = . 01 
Options: a ) . 9 , b ) . 09 , c ) . 009 , d ) . 0009 , e ) none of them
[EX A]:
a