Subject: mathqa
Question: in a mixture of 45 litres the ratio of milk to water is 4 : 1 . additional 12 litres of water is added to the mixture . find the ratio of milk to water in the resulting mixture .
Option: 
A: 2 / 3
B: 3 / 2
C: 4 / 1
D: 12 / 7
Answer: D