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: a sum was put a simple interest at a certain rate for 2 years . had it been put at 4 % higher rate , it would have fetched rs . 60 more . the sum is :
Options: a ) rs . 750 , b ) rs . 700 , c ) rs . 820 , d ) rs . 940 , e ) rs . 900
[A]: a

[Q]: Problem: 40 is subtracted from 70 % of a number , the result is 30 . find the number ?
Options: a ) 150 , b ) 997 , c ) 266 , d ) 288 , e ) 100
[A]: e

[Q]: Problem: there are two concentric circles with radii 10 and 6 . if the radius of the outer circle is increased by 20 % and the radius of the inner circle decreased by 50 % , by what percent does the area between the circles increase ?
Options: a ) 11 , b ) 111 , c ) 211 , d ) 311 , e ) 411
[A]:
b