Seawater with a concentration of 8000 g/m3 is pumped into a well-mixed tank at a rate of 0.6 m3/hr. Because of faulty design work, water is evaporating from the tank at a rate of 0.025 m3/hr. The salt solution leaves the tank at a rate of 0.6 m3/hr.
(a) If the tank originally contains 1 m3 of the inlet solution, how long after the outlet pump is turned on will the tank run dry?
(b) Use numerical methods to determine the salt concentration in the tank as a function of time.