Task: Question Answering
Input (English): Problem: a watch was sold at a loss of 15 % . if it was sold for rs . 400 more , there would have been a gain of 5 % . what is the cost price ? 
Options: a ) 1600 , b ) 2998 , c ) 2778 , d ) 2788 , e ) 2991
Output (English): a