(2 points) A tank contains 90 kg of salt and 2000 L of water. Pure water enters a tank at the rate 6 L/min. The solution is mixed and drains from the tank at the rate 3 L/min. (a) What is the amount of salt in the tank initially? A(0)= 90 kg (kg of salt) (b) Enter an expression for the total amount of brine (salt-water) in the tank at a time t minutes after this process starts? Total number of liters of brine at time t = L (L of brine) (c) Let A represent the number of kg of salt in the tank at time t. Enter an expression for the concentration of salt in the tank at a time t minutes after this process starts? Concentration: c(t)= kg/L (kg of salt per L of brine) (d) Enter a differential equation to represent the rate at which the amount of salt is changing in the tank at time t. dAdt= (e) Solve this differential equation and use the initial conditions to enter the model that gives the amount of salt in the tank at time t. A(t)= (f) Find the amount of salt in the tank after 2 hours. Amount = kg (g) 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