(Solved): A tank contains 90kg of salt and 1000L of water. Pure water enters a tank at the rate 12L/mi ...

A tank contains $90\mathrm{kg}$ of salt and $1000\mathrm{L}$ of water. Pure water enters a tank at the rate $12\mathrm{L}/\min$. The solution is mixed and drains from the tank at the rate $6\mathrm{L}/\min$. (a) What is the amount of salt in the tank initially? amount $=$ $(\mathrm{kg})$ (b) Find the amount of salt in the tank after 2.5 hours. amount $=$ ( $\mathrm{kg})$ (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)