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 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 %

Output: e

Input: Consider Input: Problem: if it is assumed that 60 percent of those who receive a questionnaire by mail will respond and 900 responses are needed , what is the minimum number of questionnaires that should be mailed ?
Options: a ) 1300 , b ) 1350 , c ) 1400 , d ) 1450 , e ) 1500

Output: e

Input: Consider Input: Problem: if the selling price of 50 articles is equal to the cost price of 20 articles , then the loss or gain percent is :
Options: a ) 45 % , b ) 23 % , c ) 20 % , d ) 60 % , e ) 56 %
Output: d