Consider the brine tanks A, B and C given in the figure. Tank A initially have 20 liters of brine made with 20 kg of salt. Tank B, initially contains 40 liters of brine with 40 kg of salt and tank C initially contains 60 liters of brine with 60 kg of salt. It is supposed that pure water enters tank A at a rate of 10 liters/min, drains from A to B at a rate of 10 liters/min, drains from B to C at a rate of 10 liters/min, and then drains from tank C at a rate of 10 liters/min. Hence, the volumes of the tanks remain constant. Find the amount of salt at any given time in the tanks. water