What diameter of cast-iron pipe is needed to carry water at a rate of 10 cfs between two reservoirs that are 2 miles apart and the elevation difference between the water surfaces is 20 ft

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches.approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *