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: a man buys an article for $ 10 . and sells it for $ 30 . find the gain percent ? 
Options: a ) 25 % , b ) 50 % , c ) 20 % , d ) 150 % , e ) 300 %
e

Problem: two numbers are respectively 50 % and 100 % more than a third number . the percentage that is first of the second is ? 
Options: a ) 65 % , b ) 83 % , c ) 27 % , d ) 42 % , e ) 75 %
e

Problem: one fourth of one third of two fifth of a number is 20 . what will be 40 % of that number 
Options: a ) a ) 140 , b ) b ) 150 , c ) c ) 180 , d ) d ) 240 , e ) e ) 220

d