Task: Question Answering
Input (English): Problem: the average monthly income of a and b is rs . 5050 . the average monthly income of b and c is rs . 6250 and the average monthly income of a and c is rs . 5200 . what is the monthly income of a ? 
Options: a ) 2000 , b ) 3000 , c ) 4000 , d ) 5000 , e ) 6200
Output (English): c