(1 point) A tank contains 100 kg of salt and 2000 L of water. Water containing $0.3 \frac{kg}{L}$ of salt enters the tank at the rate $10 \frac{L}{min}$. The solution is mixed and drains from the tank at the rate $2 \frac{L}{min}$. $A(t)$ is the amount of salt in the tank at time $t$ measured in kilograms.
(a) $A(0) = \text{____} (kg)$
(b) A differential equation for the amount of salt in the tank is $\text{____} = 0$. (Use $t, A, A', A''$, for your variables, not $A(t)$, and move everything to the left hand side.)
(c) The integrating factor is $\text{____}$
(d) $A(t) = \text{____} (kg)$
(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 $= \text{____} \frac{kg}{L}$