A tank initially contains 100 liters of a salt solution with a concentration of 0.1 g/liter. A solution with a salt concentration of 0.3 g/liter is added to the tank at 5 liters/min, and the resulting...

Extracted text: A tank initially contains 100 liters of a salt solution with a concentration of 0.1 g/liter. A solution with a salt concentration of 0.3 g/liter is added to the tank at 5 liters/min, and the resulting mixture is drained out at the same rate. Find the concentration K(t) of salt in the tank as a function of t.