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: there is 60 lit of milk and water in which milk forms 84 % . howmuch water must be added to this solution to make it solution in which milk forms 64 % 
Options: a ) 18.75 , b ) 19.75 , c ) 20.75 , d ) 21.75 , e ) 22.75
a

Problem: the true discount on a bill of rs . 2460 is rs . 360 . what is the banker ' s discount ? 
Options: a ) rs . 432 , b ) rs . 422 , c ) rs . 412 , d ) rs . 442 , e ) none of these
b

Problem: working together at their respective constant rates , machine a and machine b can produce 1,500 units in 8 hours . working alone , machine b would complete that same output in 50 % more time . if machine a were to work on its own for an 8 - hour shift , what percent of the 1,500 unit total would it produce ? 
Options: a ) 25 , b ) 36 , c ) 30 , d ) 67 , e ) 75

c