Question

At 7.15 cents per kilowatt-hour, what does it cost to leave a 75.0W light burning 24.0 hours a day?

Answer 1

75W for 24 hours
=0.075 kW for 24 hours
=1.8 kW for 1 hour
=1.8 kW-h
How much would that cost?

Answer 2

1KWh=7.35cents
1.8KWh=
1.8×7.35=13.23cents