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: how long will a boy take to run round a square field of side 50 meters , if he runs at the rate of 10 km / hr ? 
Options: a ) 52 sec , b ) 45 sec , c ) 72 sec , d ) 25 sec , e ) 39 sec
[EX A]: c

[EX Q]: Problem: you hold some gold in a vault as an investment . over the past year the price of gold increases by 40 % . in order to keep your gold in the vault , you must pay 5 % of the total value of the gold per year . what percentage has the value of your holdings changed by over the past year . 
Options: a ) 35 % , b ) 33 % , c ) 36 % , d ) 38 % , e ) 40 %
[EX A]: b

[EX Q]: Problem: a dishonest dealer professes to sell goods at the cost price but uses a weight of 600 grams per kg , what is his percent ? 
Options: a ) 28 % , b ) 66.7 % , c ) 55 % , d ) 28 % , e ) 55 %
[EX A]:
b