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: the population of a town is 30000 . it decreases annually at the rate of 20 % p . a . what will be its population after 2 years ? 
Options: a ) 4300 , b ) 19200 , c ) 5120 , d ) 5230 , e ) 5366
[EX A]: b

[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: a dress on sale in a shop is marked at $ d . during the discount sale its price is reduced by 15 % . staff are allowed a further 10 % reduction on the discounted price . if a staff member buys the dress what will she have to pay in terms of d ? 
Options: a ) 0.75 d , b ) 0.76 d , c ) 0.765 d , d ) 0.775 d , e ) 0.805 d
[EX A]:
c