The Plumber. A plumber was called to a factory to clear a clogged water line. When
he arrived, he walked around the factory to assess the situation, then
walked up to one of the pipes, tapped his wrench on it several times, and
the water line was instantly cleared. “Your problem is fixed,” he told
the factory’s general manager, and handed him a bill for $525. “Five hundred
twenty-five dollars!” the incredulous manager fumed. “You were only here
five minutes and all you did was tap on a pipe!” The plumber calmly and
confidently replied, “The $25 is for tapping the pipe. The $500 is for
knowing which pipe to tap.”