A vessel having a capacity of 100 litres contains a milk water solution having 80% Milk. The Milkman asks hi son to add a certain quantity of water to the vessel to reduce the concentration of milk to 60%. the son by mistake added the same quantity of milk to the vessel equal to quantity of water he was asked to add. realizing his mistake, he added twice the quantity of water he was asked to add initially. what was the concentration of milk in the vessel