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: walking 7 / 6 of his usual rate , a boy reaches his school 3 min early . find his usual time to reach the school ? 
Options: a ) 21 , b ) 28 , c ) 99 , d ) 77 , e ) 66
[EX A]: a

[EX Q]: Problem: find the compound interest on $ 800 for 1 year at 10 % p . a . if ci is component yearly ? 
Options: a ) $ 40 , b ) $ 400 , c ) $ 840 , d ) $ 800 , e ) $ 80
[EX A]: a

[EX Q]: Problem: what percent of 17 is 17 percent of 1 ? 
Options: a ) 0.001 , b ) 0.01 , c ) 0.1 , d ) 14 , e ) 1
[EX A]:
e