Mixture = 120 litre, Water = 25% Quantity of water = $$frac{25}{100} imes 120 = 30$$ litre And milk = 120 - 30 = 90 litre After selling 20 litre of mixture, remaining mixture = 100 litre In 100 litre of mixture, amount of milk and water will remain in the same percent. Water = $$frac{25}{100} imes 100 = 25$$ litre And milk = 100 - 25 = 75 litre Now, he added 16.2 litre of milk and 3.8 litre of water. Milk = 75 + 16.2 = 91.2 litre And water = 25 + 3.8 = 28.8 litre Total new mixture = 120 litre $$ herefore$$ Required % = $$frac{28.8}{120} imes 100 = 24 \%$$