Task: Question Answering
Input (English): Problem: a and b start a business jointly . a invests rs 16000 for 8 month and b remains in the business for 4 months . out of total profit , b claims 2 / 7 of the profit . how much money was contributed by b ? 
Options: a ) 12800 , b ) 13000 , c ) 11500 , d ) 12500 , e ) 12000
Output (English): a