Afish tank initially contains 35 liters of pure water. brine of constant, but unknown, concentration of salt is flowing in at 2 liters per minute. the solution is mixed well and drained at 2 liters per minute. be the amount of salt, in grams, in the fish tank after minutes have elapsed. find a formula for the rate of change in the amount of salt, da/dt, in a. let and the unknown concentration of incoming brine c. the amount f salt in the solution terms da grams/minute dt b. find a formula for the amount of salt, in grams, after t minutes have elapsed. your answer should be in terms of c and t (t grams c. in 40 minutes there are 20 grams of salt in the fish tank. what is the concentration of salt in the incoming brine?