In: Advanced Math
4. Consider a mixing tank with a volume of 50 gallons which is initially filled with 10 gallons of fresh water. Suppose there is an inflow pipe which pumps in a 1 lb/gallon brine (salt/water) mixture at a rate of 4 gallons per minute, and there is an outflow pipe which removes the mixture from the tank at a rate of 2 gallons per minute.
(a) Use the given information to derive an initial value problem which models the amount of salt in the tank as a function of time.
(b) Find the solution of the initial value problem.
(c) How much salt in the tank when the tank is full?