Four vessels of equal size are filled with mixtures of milk and water. The strength of milk in the four vessels are 80%, 75%, 60% and 50% respectively. If all four mixtures are mixed together then what is the ratio of milk to water in the resultant mixture?

• A. 53 : 27
• B. 13 : 27
• C. 29 : 51
• D. 3 : 5