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: rs 3600 is divided into two parts such that one part is put out at 3 % and the other at 5 % . if the annual interest earned from both the investments be rs 144 , find the first part . 
Options: a ) s 4000 , b ) s 2800 , c ) s 1800 , d ) s 3500 , e ) s 3100
[EX A]: c

[EX Q]: Problem: if the difference between the compound interest & simple interest of a certain sum of money is rs . 72 at 12 % p . a . per two year . find the sum ( in rs . ) ? 
Options: a ) 200 / 15 , b ) 200 / 17 , c ) 220 / 17 , d ) 240 / 17 , e ) 260 / 17
[EX A]: b

[EX Q]: Problem: what is the rate percent when the simple interest on rs . 800 amount to rs . 160 in 5 years ? 
Options: a ) 5 % , b ) 7 % , c ) 9 % , d ) 2 % , e ) 4 %
[EX A]:
e