Consider a conical tank, where the height of the tank is 12 meters, and and the diameter of the tank at the top is 8 meters. Water is leaking out of the bottom of a conical tank at an constant rate of 20,000 LaTeX: \text{cm}^3 / \text{min}cm 3 / min. Water is also being pumped in to the tank at a constant unknown rate (call it LaTeX: kk). The water level is currently 8 meters high, and the water level is rising at a rate of 2 LaTeX: \text{cm} / \text{min}cm / min. Find the rate LaTeX: kk at which water is being pumped in to the tank.