Diff. Eq. A tank initially contains 50 gallons of brine, with 30 pounds of salt in solution. Water runs into the tank at 6 gallons per minute and the well-stirred solution runs out at 5 gallons per minute. How long will it be until there are 25 pounds of salt in the tank?

Question

Diff. Eq.   A tank initially contains 50 gallons of brine, with 30 pounds of salt in solution. Water runs into the tank at 6 gallons per minute and the well-stirred solution runs out at 5 gallons per minute. How long will it be until there are 25 pounds of salt in the tank?

johnweldon1993 · Answer

S(0) = 30lb
B(0) = 50 gal

rate in = 6gal/min
amount of salt in = 0
rate out = 5 gal/min
amount of salt out = s/?

The thing that confuses me is that there is no volume of the tank. also there are more than 1 variable..

just starting out in the class