A cylindrical tank contains 500 liters of water in the beginning. At time =0, a hole is drilled near the bottom of the tank, and water is being drained from the tank. Assume that the volume of water remainingin the tank after minutes is
()=500(1-/60)², () , (ℎ 0≤≤60 ).
Evaluate the rate of change in the volume of water in the tank at the instant =31 (mins).