Task: Question Answering
Input (English): Problem: in a mixture of 45 litres the ratio of milk to water is 4 : 1 . additional 23 litres of water is added to the mixture . find the ratio of milk to water in the resulting mixture . 
Options: a ) 9 / 8 , b ) 4 / 1 , c ) 2 / 3 , d ) 3 / 4 , e ) 3 / 2
Output (English): a