a 540 gallon (gal) tank is filled with water in which 42 pounds (lbs) of salt is dissolved. fresh water flows into this tank at a rate of 5.5 gal/min and the well mixed solution drains at a rate of 5.5 gal/min. let be the amount of salt in pounds in the salt at time in minutes, then the amount of salt in this tank is described by the differential equation: solve this seperable differential equation for the amount of salt in the tank at time . how long until only 6 pounds of salt remain? minutes
