Three tanks are filled with a dye solution. Tanks A and B initially contains 20 hg of dye and tank C is initially pure water. A solution that contains 3 hg/L of dye is pumped into tank A at a rate of 50 L/hr. The solution in tank A flows out to tank B at a rate of 40 L/hr and out an exhaust spout at a rate of 20 L/hr. The solution in tank B into tank A at a rate of 10 L/hr, into tank C at a rate of 30 L/hr, and out an exhaust spout at a rate of 10 L/hr. The solution in tank C flows into tank B at a rate of 10 L/hr and out an exhaust spout at a rate of 20 L/hr. If tank A holds 200 L, tank B holds 100 L, and tank C holds 100 L, set up a system to determine the amount of dye in each tank at a given time t.