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: peter invested a certain sum of money in a simple interest bond whose value grew to $ 100 at the end of 2 years and further to $ 200 at the end of another 4 years . what was the rate of interest in which he invested his sum ? 
Options: a ) 50 % , b ) 25 % , c ) 10 % , d ) 30 % , e ) 18 %
[A]: a


[Q]: Problem: a 13 % stock yields 8 % . the market value of the stock is : 
Options: a ) rs . 72 , b ) rs . 92 , c ) rs . 162.50 , d ) rs . 116.50 , e ) none of these
[A]: c


[Q]: Problem: jackie has two solutions that are 4 percent sulfuric acid and 12 percent sulfuric acid by volume , respectively . if these solutions are mixed in appropriate quantities to produce 60 liters of a solution that is 5 percent sulfuric acid , approximately how many liters of the 12 percent solution will be required ? 
Options: a ) 18 , b ) 20 , c ) 24 , d ) 33.75 , e ) 42
[A]:
d