Amount of milk in the initial mixture = 75% of 120 liters = 90 liters Amount of water in the initial mixture = 120 - 90 = 30 liters When 30 liters of the mixture is replaced by water, the amount of milk removed = 75% of 30 liters = 22.5 liters So, the remaining milk = 90 - 22.5 = 67.5 liters The total volume of the mixture remains 120 liters, but now the water is 30 liters (original) + 30 liters (added) = 60 liters Percentage of milk in the new mixture = (67.5/120) × 100 = 56.25% ≈ 56%
X can do a piece of work in 30 days. He worked at it for 5 days and then Y finished it in 20 days. In how many days can X and Y together finish the work?