７３、The following appeared in a letter from the owner of the Sunnyside Towers apartment building to its manager.

　　One month ago, all the showerheads on the first five floors of Sunnyside Towers were modified to restrict the water flow to approximately 1/3 of its original force. Although actual readings of water usage before and after the adjustment are not yet available, the change will obviously result in a considerable savings for Sunnyside Corporation, since the corporation must pay for water each month. Except for a few complaints about low water pressure, no problems with showers have been reported since the adjustment. Clearly, restricting water flow throughout all the 20 floors of Sunnyside Towers will increase our profits further.