Task: Question Answering
Input (English): Problem: workers decided to raise rs . 3 lacs by equal contribution from each . had they contributed rs . 50 eachextra , the contribution would have been rs . 3.20 lacs . how many workers were they ? 
Options: a ) 220 , b ) 400 , c ) 500 , d ) 560 , e ) 590
Output (English): b