Before discrediting the test authors, I comment on the possibility of exam instructions or directions by the instructor about what the test covers. Such as materials from chapters so and so in the text book. Huge assumptions that can never be made in real life are often made in test questions.
I could select any single answer from those four and write BS to justify the correctness. An account with multiple facilities that size wouldn't be billed on just energy charge. If I so wanted I could place these 20 bulbs in some place used only by drama or theatre department only and schedule the class to meet in coincidence with the school's historical peak usage period so the added demand stands on top of the summit. I'll choose the rate schedule from wherever I want.
The class could only meet for 6 hours a month and i could make it appear on paper as $200 a year difference by the cost of 1.1 x kW demand charge.
In a school, twenty 75-watt incandescent lights were replaced with twenty 20-watt fluorescent bulbs. If they pay $0.10/KWH, how much will they save in a year?
Well the question didn't ask how much they would save on
energy charge. Realistically, where are incandescent lamps still used in schools aside from janitorial closets or theater/stage departments?
