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: average monthly income of a family of 3 earning members was rs . 735 . one of the earning members died and therefore , the average income came down to rs 650 . the income of the deceased was ? 
Options: a ) rs . 692.80 , b ) rs . 905 , c ) rs . 990 , d ) rs . 1385 , e ) none
[EX A]: b

[EX Q]: Problem: solution x is 10 percent alcohol by volume , and solution y is 30 percent alcohol by volume . how many milliliters of solution y must be added to 50 milliliters of solution x to create a solution that is 25 percent alcohol by volume ? 
Options: a ) 150 , b ) 500 / 3 , c ) 400 , d ) 480 , e ) 600
[EX A]:
a