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 of money at simple interest amounts to rs . 815 in 3 years and to rs . 865 in 4 years . the sum is : 
Options: a ) s . 665 , b ) s . 690 , c ) s . 698 , d ) s . 700 , e ) s . 720
[A]: a


[Q]: Problem: the price of a book is increased from $ 300 to $ 480 . what is the % of increase in its price ? 
Options: a ) 10 % , b ) 20 % , c ) 40 % , d ) 50 % , e ) 60 %
[A]: e


[Q]: Problem: we had $ 2800 left after spending 30 % of the money that we took for shopping . how much money did we start with ? 
Options: a ) $ 3700 , b ) $ 4000 , c ) $ 4300 , d ) $ 4600 , e ) $ 4900
[A]:
b