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'.

[Q]: Problem: 3 seventh of a number is 12 more than 40 % of that number . what will be the 30 % of that number ? 
Options: a ) a ) 148 , b ) b ) 210 , c ) c ) 63 , d ) d ) 248 , e ) e ) 258
[A]: c


[Q]: Problem: what percent of 12.4 kg is 20 gms ? 
Options: a ) 25 , b ) 16 , c ) 18 , d ) 19 , e ) 17
[A]: b


[Q]: Problem: a tank contains 6,500 gallons of a solution that is 5 percent sodium chloride by volume . if 2,500 gallons of water evaporate from the tank , the remaining solution will be approximately what percent sodium chloride ? 
Options: a ) 5.12 % , b ) 6.12 % , c ) 7.12 % , d ) 8.12 % , e ) 9.12 %
[A]:
d