A tank contains Si] kg of salt and l L of water. A solution of a concentration i104 kg of salt per liter enters a tank at the rate 5 Limin. The solution is mixed and drains from the tank at the same rate. {a} What is the concentration of our solution in the tank initially? {b} Find the amount of salt in the tank after 4 hours. {:1 Find the concentration of salt in the solution in the tank as time approaches infinity