Suppose a brine containing 0.2kg of salt per liter runs into a tank initially filled with 750L of water containing 5kg of salt. The brine enters the tank at a rate of 5L/min. The mixture, kept uniform by stirring, is flowing out at the rate of 5L/min. Complete parts (a) and (b). (a) Find the concentration, in kilograms per liter, of salt in the tank after 5min. [Hint: Let A denote the number of kilograms of salt in the tank at t minutes after the process begins and use the fact that rate of increase in A= rate of input - rate of exit.] The concentration of salt in the tank after 5min will be kg/L. (Round to four decimal places as needed.)