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: mary works in a restaurant a maximum of 70 hours . for the first 20 hours , she is paid $ 8 per hour . for each overtime hour , she is paid at a rate which is 25 % higher than her regular rate . how much mary can earn in a week ? 
Options: a ) 600 , b ) 620 , c ) 660 , d ) 320 , e ) 400
[EX A]: c

[EX Q]: Problem: if the cost price of 50 articles is equal to the selling price of 15 articles , then the gain or loss percent is ? 
Options: a ) 16 , b ) 127 , c ) 12 , d ) 18 , e ) 233
[EX A]: e

[EX Q]: Problem: in an election only two candidates contested . a candidate secured 70 % of the valid votes and won by a majority of 180 votes . find the total number of valid votes ? 
Options: a ) 450 , b ) 570 , c ) 480 , d ) 520 , e ) 550
[EX A]:
a