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 merchant sells an item at a 20 % discount , but still makes a gross profit of 20 percent of the cost . what percent p of the cost would the gross profit on the item have been if it had been sold without the discount ? 
Options: a ) 20 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 75 %
[EX A]: c

[EX Q]: Problem: if each edge of cube increased by 30 % , the percentage increase in 
Options: a ) 69 , b ) 72 , c ) 64 , d ) 61 , e ) 75
[EX A]: a

[EX Q]: Problem: a merchant sells an item at a 20 % discount , but still makes a gross profit of 20 percent of the cost . what percent e of the cost would the gross profit on the item have been if it had been sold without the discount ? 
Options: a ) 20 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 75 %
[EX A]:
c