In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: a and b invests rs . 3000 and rs . 4500 respectively in a business . if a doubles his capital after 6 months . in what ratio should a and b divide that year ' s profit ? 
Options: a ) 6 : 8 , b ) 9 : 8 , c ) 7 : 9 , d ) 9 : 5 , e ) 1 : 1
[EX A]: e

[EX Q]: Problem: raman ' s salary was decreased by 50 % and subsequently increased by 50 % . how much percent does he loss . 
Options: a ) 75 , b ) 65 , c ) 45 , d ) 25 , e ) 85
[EX A]: d

[EX Q]: Problem: a survey was sent to 70 customers , 7 of whom responded . then the survey was redesigned and sent to another 63 customers , 9 of whom responded . by approximately what percent did the response rate increase from the original survey to the redesigned survey ? 
Options: a ) 2 % , b ) 6 % , c ) 4 % , d ) 28 % , e ) 63 %
[EX A]:
c