Task: Question Answering
Input (English): Problem: in what ratio p : q should the mixture p of milk and water in the ratio of 6 : 1 be mixed with another mixture q of milk and water in the ratio 3 : 4 so that the resultant mixture contains equal quantities of milk and water ? 
Options: a ) 1 : 3 , b ) 1 : 4 , c ) 1 : 5 , d ) 2 : 5 , e ) 3 : 4
Output (English): c