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'.

Problem: by selling an article for $ 110 , a person gains $ 10 . what is the gain % ? 
Options: a ) 25 % , b ) 30 % , c ) 50 % , d ) 20 % , e ) 10 %
e

Problem: in a certain city , 70 percent of the registered voters are democrats and the rest are republicans . in a mayoral race , if 80 percent of the registered voters who are democrats and 30 percent of the registered voters who are republicans are expected to vote for candidate a , what percent of the registered voters are expected to vote for candidate a ? 
Options: a ) 65 % , b ) 52 % , c ) 85 % , d ) 69 % , e ) 75 %
a

Problem: an error 1 % 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 ) 2.01 , b ) 30.1 , c ) 3.01 , d ) 25.01 , e ) 4.05

a