Three new cast iron pipes, having diameters of 24, 21 and 18 in respectively, each 450-ft long, are connected in series. The 24-in pipe leads from a reservoir (flush entrance), and the 18-in pipe discharges into the air at a point 15 ft lower than the reservoir water surface level. Assuming all changes in section to be abrupt, find the rate of discharge of water at 60 degrees Fahreneit.