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: an error 2 % 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 ) 1.04 , b ) 2.04 , c ) 3.04 , d ) 4.04 , e ) none of these
[EX A]: d

[EX Q]: Problem: to produce an annual income of rs . 800 from a 8 % stock at 90 , what is the amount of stock needed ? 
Options: a ) 10000 , b ) 11000 , c ) 12000 , d ) 13000 , e ) 14000
[EX A]: a

[EX Q]: Problem: a merchant marks his goods up by 30 % and then offers a discount of 20 % on the marked price . what % profit does the merchant make after the discount ? 
Options: a ) 8 % , b ) 10 % , c ) 21 % , d ) 15 % , e ) 4 %
[EX A]:
e