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 10 % in excess is made while measuring the side of a square . now what is the percentage of error in the calculated area of the square ? 
Options: a ) 6.64 % , b ) 16.64 % , c ) 15.64 % , d ) 21 % , e ) 10.64 %
[EX A]: d

[EX Q]: Problem: at a particular graduation party with 300 guests , 70 % of the guests brought gifts , and 40 % of the female guests brought gifts . if 30 males did not bring gifts to the party , how many females did bring gifts ? 
Options: a ) 18 , b ) 28 , c ) 40 , d ) 68 , e ) 70
[EX A]: c

[EX Q]: Problem: the present population of a town is 3456 . population increase rate is 20 % p . a . find the population of town before 2 years ? 
Options: a ) 2400 , b ) 2100 , c ) 3500 , d ) 3600 , e ) 2050
[EX A]:
a