Oil spilled from a ruptured tanker spreads in a circle whose area increases at a constant rate of 9 mi2/hr. How rapidly is radius of the spill increasing when the area is 4 mi2

Marion has a bicycle that she is planning to take for a ride. the rim of the rear wheel lies 41 cm from the center of the wheel. the tire itself has a thickness of 3 cm. in order for marion to ride her bicycle 96,712 cm approximately how many rotations will the rear wheel make?