A flotation cell is fed with solids at the rate of 250tph with a pulp having a density of 1.35. Material solid density is 3.2. The concentrate contains 15% of the feed solids mass and it has a pulp density of 1.15. The concentrate solid density is 3.5. How much water must be added to the tails to give an L/S ratio of 1.25. Give your assumptions and continue answering.