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'.

[EX Q]: Problem: tickets to a certain concert sell for $ 20 each . the first 10 people to show up at the ticket booth received a 40 % discount , and the next 20 received a 15 % discount . if 50 people bought tickets to the concert , what was the total revenue from ticket sales ? 
Options: a ) $ 600 , b ) $ 740 , c ) $ 860 , d ) $ 980 , e ) $ 1,140
[EX A]: c

[EX Q]: Problem: how is 4 % expressed as a decimal fraction ? 
Options: a ) 0.4 , b ) 0.04 , c ) 0.004 , d ) 0.0004 , e ) 4
[EX A]: b

[EX Q]: Problem: reena took a loan of $ . 1200 with simple interest for as many years as the rate of interest . if she paid $ 300 as interest at the end of the loan period , what was the rate of interest ? 
Options: a ) 5 , b ) 6 , c ) 18 , d ) can not be determined , e ) none of these
[EX A]:
a