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: at what rate percent of simple interest will a sum of money double itself in 22 years ? 
Options: a ) 6.54 % , b ) 4.54 % , c ) 8 . 2 % , d ) 4.94 % , e ) 5.54 %
[EX A]: b

[EX Q]: 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
[EX A]: e

[EX Q]: Problem: what percent is 120 of 80 ? 
Options: a ) 150 % , b ) 134 1 / 3 % , c ) 135 1 / 3 % , d ) 140 1 / 3 % , e ) 143 1 / 3 %
[EX A]:
a