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: find the principle on a certain sum of money at 5 % per annum for 3 1 / 5 years if the amount being rs . 580 ? 
Options: a ) rs . 500 , b ) rs . 5100 , c ) rs . 530 , d ) rs . 540 , e ) none of these
[EX A]: a

[EX Q]: Problem: if 3 x – 5 y = 5 and x / x + y = 5 / 7 , then what is the value of x – y ? 
Options: a ) 9 , b ) 6 , c ) 4 , d ) 3 , e ) none of these
[EX A]: d

[EX Q]: Problem: if | 5 x - 5 | = 150 , what is the sum of all the possible values of x ? 
Options: a ) 2 , b ) - 2 , c ) 6 , d ) - 3 , e ) 5
[EX A]:
a