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'.

[Q]: Problem: the simple interest on a certain sum of money for 2 years at 10 % per annum is half the compound interest on $ 100 for 2 years at 5 % per annum . the sum placed on simple interest is ? 
Options: a ) $ 602.5 , b ) $ 625.8 , c ) $ 710.6 , d ) $ 745 , e ) $ 790.3
[A]: a


[Q]: Problem: a dishonest dealer professes to sell goods at the cost price but uses a weight of 840 grams per kg , what is his percent ? 
Options: a ) 19 , b ) 25 , c ) 77 , d ) 88 , e ) 11
[A]: a


[Q]: Problem: from january 1 , 1991 , to january 1 , 1993 , the number of people enrolled in health maintenance organizations increased by 15 percent . the enrollment on january 1 , 1993 , was 60 million . how many million people , to the nearest million , were enrolled in health maintenance organizations on january 1 , 1991 ? 
Options: a ) 38 , b ) 39 , c ) 40 , d ) 41 , e ) 52
[A]:
e