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'.

Input: Consider Input: Problem: a number increased by 20 % gives 480 . the number is ? 
Options: a ) 200 , b ) 300 , c ) 400 , d ) 500 , e ) 600

Output: c


Input: Consider Input: Problem: in an acoustics class , 120 students are male and 100 students are female . 25 % of the male students and 20 % of the female students are engineering students . 20 % of the male engineering students and 25 % of the female engineering students passed the final exam . what percentage of engineering students passed the exam ? 
Options: a ) 5 % , b ) 10 % , c ) 16 % , d ) 22 % , e ) none of these

Output: d


Input: Consider Input: Problem: a feed store sells two varieties of birdseed : brand a , which is 40 % millet and 60 % sunflower , and brand b , which is 65 % millet and 35 % sunflower . if a customer purchases a mix of the two types of birdseed that is 50 % sunflower , what percent of the mix is brand a ? 
Options: a ) 40 % , b ) 45 % , c ) 50 % , d ) 55 % , e ) 60 %


Output: e