A tank contains 90 kg of salt and 2000 L of water. Pure water enters a tank at the rate 8 L/min. The solution is mixed and drains from the tank at the rate 4 Umin.
(a) What is the amount of salt in the tank initially?
amount = ...................... (kg)
(b) Find the amount of salt in the tank after 4.5 hours.
amount = ...................... (kg)
(c) Find the concentration of salt in the solution in the tank as time approaches infinity. (Assume your tank is large enough to hold all the solution.)
concentration = ................. (kg/L)