A tank contains $60$ kg of salt and $2000$ L of water. Water containing $0.6\frac{kg}{L}$ of salt enters the tank at the rate $10$ $\frac{L}{min}$. The solution is mixed and drains from the tank at the rate $5$ $\frac{L}{min}$. A(t) is the amount of salt in the tank at time t measured in kilograms.

(a) A(0) = (kg)

(b) A differential equation for the amount of salt in the tank is $= 0$. (Use t,A, A', A'', for your variables, not A(t), and move everything to the left hand side.)
(c) The integrating factor is
(d) A(t) = (kg)

(e) 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 = $\frac{kg}{L}$