John uses a 75-watt electric fan for 8 hours a day. How much kWh of electric energy does he consume per month (30 days) for using the electric fan? Let's be accurate as possible.
In a day, John uses 75x 8 = 600 watts. So in a month, he uses 600 x 30 = 18 000 watts. Since there are 1000 watts in 1 kilowatt, then John uses 18000 / 1000 = 18.
The answer: 18.