A. Consider the two tanks: tank A contains 20 gallons of pure water. Suppose tank B contains 10 gallons of water in which 4 pounds of salt is dissolved. Liquid is pumped into and out of the tanks as indicated in the following figure; the mixture exchanged between the two tanks and the liquid pumped out of tank B are assumed to be well stirred. Determine the number of pounds of salt in tanks A and B, respectively, at time 5 min. Water of 5 pounds of salt per gal 3 gal/min Mixture 2 gal/min Mixture 5 gal/min Mixture 3 gal/min