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

[EX Q]: Problem: an error 4 % in excess is made while measuring the side of a square . the percentage of error in the calculated area of the square is : 
Options: a ) 4.16 , b ) 5.16 , c ) 7.16 , d ) 8.16 , e ) 9.16
[EX A]: d

[EX Q]: Problem: when sold at a 50 % discount , a sweater nets the merchant a 40 % profit on the wholesale cost at which he initially purchased the item . by what % is the sweater marked up from wholesale at its normal retail price ? 
Options: a ) 20 % , b ) 64.29 % , c ) 70 % , d ) 80 % , e ) 100 %
[EX A]:
b