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'.

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 %
d

Problem: the profit earned by selling an article for rs . 753 is equal to the loss incurred when the same article is sold for rs . 455 . what should be the sale price for making 50 % profit ? 
Options: a ) 706 , b ) 786 , c ) 906 , d ) 896 , e ) 696
c

Problem: a and b invests rs . 10000 each , a investing for 9 months and b investing for all the 12 months in the year . if the total profit at the end of the year is rs . 21000 , find their shares ? 
Options: a ) 1300,1500 , b ) 9000,12000 , c ) 7290,8000 , d ) 15000,12000 , e ) 72821,75000

b