Task: Question Answering
Input (English): Problem: if 10 litres of an oil of rs . 50 per litres be mixed with 5 litres of another oil of rs . 68 per litre then what is the rate of mixed oil per litre ? 
Options: a ) rs . 49.17 , b ) rs . 51.03 , c ) rs . 56 , d ) rs . 55.33 , e ) none of the above
Output (English): c