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: by selling 10 pencils for a rupee a man loses 15 % . how many for a rupee should he sell in order to gain 15 % ? 
Options: a ) 8.39 , b ) 6.39 , c ) 7.39 , d ) 9.39 , e ) 2.39
[EX A]: c

[EX Q]: Problem: solve the quickfire maths brain teaser â ˆ š 25 % = ? 
Options: a ) 30 % , b ) 40 % , c ) 50 % , d ) 19 % , e ) 29 %
[EX A]: c

[EX Q]: Problem: by weight , liquid x makes up 0.8 percent of solution a and 1.8 percent of solution b . if 400 grams of solution a are mixed with 700 grams of solution b , then liquid x accounts for what percent of the weight of the resulting solution ? 
Options: a ) 1.58 % , b ) 1.98 % , c ) 10 % , d ) 15 % , e ) 19 %
[EX A]:
a