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: in an election between two candidates , one got 60 % of the total valid votes , 30 % of the votes were invalid . if the total number of votes was 9000 , the number of valid votes that the other candidate got , was : 
Options: a ) 2500 , b ) 2520 , c ) 3000 , d ) 3100 , e ) none of these
[EX A]: b

[EX Q]: Problem: a bowl of fruit contains 10 apples and 23 oranges . how many oranges must be removed so that 50 % of the pieces of fruit in the bowl will be apples ? 
Options: a ) 3 , b ) 13 , c ) 14 , d ) 17 , e ) 20
[EX A]: b

[EX Q]: Problem: a man took a loan at rate of 12 % per annum simple interest . after 3 years he had to pay 6480 interest . the principal amount borrowed by him was . 
Options: a ) rs 14000 , b ) rs 15000 , c ) rs 16000 , d ) rs 18000 , e ) none of these
[EX A]:
d