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: a broker invested her own money in the stock market . during the first year , she increased her stock market wealth by 60 percent . in the second year , largely as a result of a slump in the stock market , she suffered a 30 percent decrease in the value of her stock investments . what was the net increase or decrease on her overall stock investment wealth by the end of the second year ? 
Options: a ) − 5 % , b ) 5 % , c ) 12 % , d ) 20 % , e ) 80 %

A: c
****
Q: Problem: a , b and c enter into partnership . a invests some money at the beginning , b invests double the amount after 6 months , and c invests thrice the amount after 8 months . if the annual gain be rs . 21000 . a ' s share is ? 
Options: a ) 2999 , b ) 2778 , c ) 7000 , d ) 2889 , e ) 6612

A: c
****
Q: Problem: the difference between compound interest and simple interest on a certain amount of money at 5 % per annum for 2 years is 15 . find the sum : 
Options: a ) 4500 , b ) 7500 , c ) 5000 , d ) 6000 , e ) none of these

A:
d
****