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: the calendar of the year 2060 can be used again in the year ? 
Options: a ) 2081 , b ) 2083 , c ) 2088 , d ) 1971 , e ) 1973
c

Problem: running at the same constant rate , 6 identical machines can produce a total of 270 bottles per minute . at this rate , how many bottles could 8 such machines produce in 4 minutes ? 
Options: a ) 648 , b ) 1800 , c ) 2700 , d ) 1440 , e ) none of these
d

Problem: if 15 % of a is the same as 25 % of b , then a : b is : 
Options: a ) 5 : 3 , b ) 4 : 3 , c ) 7 : 16 , d ) 12 : 17 , e ) 11 : 13

a