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'.

Problem: i bought two books ; for rs . 600 . i sold one at a loss of 15 % and other at a gain of 19 % and then i found each book was sold at the same price . find the cost of the book sold at a loss ? 
Options: a ) 197 , b ) 280 , c ) 189 , d ) 278 , e ) 350
e

Problem: at an election 2 candidates are participated and a candidate got 20 % of votes and defeated by 500 . and 10 votes are invalid . find the total polled votes ? 
Options: a ) 843 , b ) 1023 , c ) 965 , d ) 413 , e ) 1245
a

Problem: a shopkeeper sold an article at $ 100 with 20 % profit . then find its cost price ? 
Options: a ) $ 120 , b ) $ 100 , c ) $ 91 , d ) $ 83 , e ) $ 69

d