Task: Question Answering
Input (English): Problem: a mixture contains milk and water in the ratio 6 : 3 . on adding 10 litters of water , the ratio of milk to water becomes 6 : 5 . the quantity of milk in the original mixture is ? 
Options: a ) 90 , b ) 45 , c ) 110 , d ) 40 , e ) 50
Output (English): b