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: a shopkeeper loses 15 % , if an article is sold for rs . 136 . what should be the selling price of the article to gain 20 % ? 
Options: a ) s . 147 , b ) s . 148 , c ) s . 144 , d ) s . 189 , e ) s . 192
[EX A]: 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: find compound interest on $ 8000 at 15 % per annum for 2 years 4 months , compounded annually . 
Options: a ) 3109 , b ) 3209 , c ) 3108 , d ) 3107 , e ) 3100
[EX A]:
a