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: machine p and machine q are each used to manufacture 660 sprockets . it takes machine p 10 hours longer to produce 660 sprockets than machine q . machine q produces 10 % more sprockets per hour than machine a . how many sprockets per hour does machine a produce ? 
Options: a ) 5 , b ) 15 , c ) 55 , d ) 95 , e ) 6
e

Problem: on a sum of money , the s . i . for 2 years is $ 600 , while the c . i . is $ 612 , the rate of interest being the same in both the cases . the rate of interest is ? 
Options: a ) 3 % , b ) 4 % , c ) 5 % , d ) 6 % , e ) 7 %
b

Problem: a reduction of 20 % in the price of salt enables a lady to obtain 25 kgs more for rs . 100 , find the original price per kg ? 
Options: a ) 6 , b ) 1 , c ) 5 , d ) 4 , e ) 7

b