A 20,000 gal. capacity tank contains 8,000 gals. ofwater/solids mixture at a density of 12 pounds per gal.(ppg). Fresh water (8.34 ppg) is added at a rate of 10 gallons per minute(gpm). At the same time fluid is being drained from the bottom ofthe tanks at 5 gpm. Assume perfect mixing what is the fluiddensity (ppg) when the tank volume equals 10,000 gals?
How much time has pasted when the density of the tank is 10ppg?