#4.) A 250-gallon tank initially holds 100 gallons of water with 2 lbs of salt. At time, t = 0, a brine solution containing 4lb of salt per gallon is introduced into the tank at the rate of 3 gallons per minute. At time, t = 30 minutes, a valve is opened at the bottom of the tank and the well- stirred mixture leaves the tank at the rate of 3 gallons per minute. a.) Find a function, Q(t), that gives the amount of salt in the tank at any time, t. This will need to be a piece-wise defined function. b.) Find the limiting value of describing the amount of salt in the tank as t>00 #4.) A 250-gallon tank initially holds 100 gallons of water with 2 lbs of salt. At time, t = 0, a brine solution containing 4lb of salt per gallon is introduced into the tank at the rate of 3 gallons per minute. At time, t = 30 minutes, a valve is opened at the bottom of the tank and the well- stirred mixture leaves the tank at the rate of 3 gallons per minute. a.) Find a function, Q(t), that gives the amount of salt in the tank at any time, t. This will need to be a piece-wise defined function. b.) Find the limiting value of describing the amount of salt in the tank as t>00