+206 A right cylindrical tank with circular bases is being filled with water at a rate of $20\pi$ cubic meters per hour. As the tank is filled, the water level rises four meters per hour. What is the radius of the tank, in meters? Express your answer in simplest radical form.
+37146 Volume of water per hour = 20 pi
volume of a cylinder = pi r^2 h
h is 4 meters
pi r^2 4 = 20 pi
r^2 4 = 20
r = sqrt 5 meters
