Part V. Mixture Problems.12. Hairy Row Kee invented a mixing tank with a 400-iter capacity for Ay See See. The tank contains a solution of 300 L of water and 100 kg of salt. A solution containing 5 kg of salt per liter is allowed to flow into the tank at the rate of 5Lmin. The mixture flows from the tank at the rate of 1Lmin.a. Determine the appropriate model equation for the amount of salt at any time t.(4 points)b. How much salt is in the tank at the end of 16 minutes? (4 points)c. When does the tank start to overflow? (4 points)