Task: Question Answering
Input (English): Problem: a shopkeeper buys two articles for rs . 1000 each and then sells them , making 50 % profit on the first article and 50 % loss on second article . find the net profit or loss percent ? 
Options: a ) 500 , b ) 768 , c ) 276 , d ) 280 , e ) 279
Output (English): a