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: 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
[EX A]: e

[EX Q]: Problem: calculate how many seconds it will take for 4 bells to toll together again , given that they begin to toll together respectively at the intervals of 9 , 10 , 14 and 18 seconds . ?
Options: a ) 636 , b ) 631 , c ) 633 , d ) 610 , e ) 630
[EX A]: e

[EX Q]: Problem: a shopkeeper has 280 kg of apples . he sells 40 % of these at 20 % profit and remaining 60 % at 20 % profit . find his % profit on total .
Options: a ) 24 % , b ) 20 % , c ) 26 % , d ) 28 % , e ) 35 %
[EX A]:
b