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: a started a business with an investment of rs . 70000 and after 6 months b joined him investing rs . 120000 . if the profit at the end of a year is rs . 13000 , then the share of b is ? 
Options: a ) 6000 , b ) 12000 , c ) 18000 , d ) 24009 , e ) 24002
[EX A]: a

[EX Q]: Problem: a merchant sells an item at a 20 % discount , but still makes a gross profit of 20 percent of the cost . what percent p of the cost would the gross profit on the item have been if it had been sold without the discount ? 
Options: a ) 20 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 75 %
[EX A]: c

[EX Q]: Problem: the difference between simple and compound interest on rs . 1600 for one year at 10 % per annum reckoned half - yearly is ? 
Options: a ) 8 , b ) 3 , c ) 9 , d ) 4 , e ) 2
[EX A]:
d