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: 30 is what percent of 100 ? 
Options: a ) 35 % , b ) 30 % , c ) 45 % , d ) 50 % , e ) 55 %
b

Problem: 120 students represent x percent of the boys at a school . if the boys at the school make up 30 % of the total school population of x students , what is x ? 
Options: a ) 120 , b ) 150 , c ) 180 , d ) 200 , e ) 250
d

Problem: how much interest will $ 10,000 earn in 9 months at an annual rate of 6 % ? 
Options: a ) $ 250 , b ) $ 350 , c ) $ 450 , d ) $ 550 , e ) $ 650

c