Problem. A light-hazard occupancy is protected by a wet-pipe sprinkler system designed by the density/area method with a design density of 0.10 gpm/ft² over a 1,500 ft² design area. What is the minimum sprinkler-system demand at the design area, excluding hose stream and friction losses?

Approach. The base demand is simply density × area = 0.10 gpm/ft² × 1,500 ft² = 150 gpm. On the real exam you would then add the required hose-stream allowance and account for friction and elevation losses back to the supply — the full method is worked in the textbook and practice exams.