A vessel of capacity 90 liters fully filled with pure milk. Nine liters milk is removed from the vessel and replaced with water. Nine liters of the solution thus formed is removed and replaced with water. Find the quantity of pure milk in the final milk solution?
Two vessels P and Q contain 62.5% and 87.5% of alcohol respectively. If 2 litres from vessel P is mixed with 4 liters from vessel Q, the ratio of alcohol and water in the resulting mixture is__?