Q. There are 2 vessels which are filled with the pure components. Vessel 1 contains 20 litres of milk and vessel 2 contains 20 litres of water, 5 litre of milk is taken from the vessel 1 and replaced in vessel 2. Then 4 litres of mixture is transferred from vessel 2 to vessel 1. Find the ratio of amount of water in vessel 1 to the amount of milk in vessel 2?

1. 7: 8
2. 8:7
3. 16 : 21
4. none of these