Task: Question Answering
Input (English): Problem: in what ratio should a variety of rice costing rs . 10 per kg be mixed with another variety of rice costing rs . 13.25 per kg to obtain a mixture costing rs . 10.75 per kg ? 
Options: a ) 2 : 1 , b ) 1 : 2 , c ) 5 : 1 , d ) 4 : 1 , e ) 3 : 1
Output (English): a