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'.

[Q]: Problem: reena took a loan of $ . 1200 with simple interest for as many years as the rate of interest . if she paid $ 588 as interest at the end of the loan period , what was the rate of interest ? 
Options: a ) 3.6 , b ) 7 , c ) 18 , d ) can not be determined , e ) none of these
[A]: b


[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 %
[A]: d


[Q]: Problem: a retailer buys 80 pens at the market price of 36 pens from a wholesaler , if he sells these pens giving a discount of 1 % , what is the profit % ? 
Options: a ) 110 , b ) 115 , c ) 112 , d ) 118 , e ) 120
[A]:
e