Solve the problem.
-What is the cost of lighting a 500-watt outdoor light for 8 hours, if electricity costs 7.5¢ per kilowatt-hour?
A)30 cents
B)60 cents
C)67 cents
D)45 cents

Question

Quizplus · Accepted Answer

The cost is calculated by multiplying the power consumption (in kilowatts) by the time (in hours) and the cost of electricity per kilowatt-hour. A 500-watt light is 0.5 kilowatts. For 8 hours, the energy consumed is 0.5 kW * 8 h = 4 kWh. At 7.5¢ per kWh, the cost is 4 kWh * 7.5¢ = 30 cents.

Solve the Problem. -What Is the Cost of Lighting a 500-Watt Outdoor Light