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: a , b and c started a business with a total investment of rs . 90000 . a invests rs . 6000 more than b and b invests rs . 3000 less than c . if the total profit at the end of a year is rs . 8640 , find b ' s share . 
Options: a ) rs . 2592 , b ) rs . 2520 , c ) rs . 2880 , d ) rs . 3360 , e ) none of these
[EX A]: a

[EX Q]: Problem: a room is 6 meters 24 centimeters in length and 4 meters 32 centimeters in width . find the least number of square tiles of equal size required to cover the entire floor of the room . 
Options: a ) 107 , b ) 117 , c ) 127 , d ) 137 , e ) 147
[EX A]: b

[EX Q]: Problem: if 5 x = 3 y and xy ≠ 0 , what is the ratio of 1 / 5 * x to 1 / 6 * y ? 
Options: a ) 25 / 6 , b ) 36 / 25 , c ) 18 / 25 , d ) 5 / 6 , e ) 25 / 36
[EX A]:
c