A tank initially contains 10 gallons of brine in which 3 pounds of salt are dissolved. A brine containing 2 lb/gal of salt runs into the tank at the rate of 2 gal/min. The mixture is well stirred and ows out of the tank at the rate of 1 gal/min.
(a) What is the volume of the brine in the tank at the time t?
(b) State and solve the I.V.P. describing this process(remember to include the initial condition).