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: during a sale , the price of a pair of shoes is marked down 15 % from the regular price . after the sale ends , the price goes back to the original price . what is the percent of increase to the nearest percent from the sale price back to the regular price for the shoes ?
Options: a ) 9 % , b ) 10 % , c ) 11 % , d ) 18 % , e ) 90 %
[EX A]: d

[EX Q]: Problem: if a lends rs . 3500 to b at 10 % per annum and b lends the same sum to c at 12 % per annum then the gain of b in a period of 3 years is ?
Options: a ) 200 , b ) 210 , c ) 220 , d ) 225 , e ) 230
[EX A]: b

[EX Q]: Problem: what percent of 75 is 45 ?
Options: a ) 0.25 % , b ) 4 % , c ) 25 % , d ) 40 % , e ) 60 %
[EX A]:
e