Question

A home uses four - 60-watt light bulbs for 5 hours per day. How many kilowatt-hours of energy are used by these lightbulbs in one month (1 month=30 days)? How much does it cost per month if electricity is $0.11 per kilowatt-hour?

Answer 1

Explanation:

The total wattage for the four light bulbs is 4 bulbs * 60 watts/bulb = 240 watts. Since 1 kilowatt is equal to 1000 watts, this is equivalent to 240/1000 = 0.24 kilowatts. If these light bulbs are used for 5 hours per day, the energy used per day is 0.24 kilowatts * 5 hours/day = 1.2 kilowatt-hours/day. Over the course of a month with 30 days, the total energy used by these light bulbs is 1.2 kilowatt-hours/day * 30 days/month = 36 kilowatt-hours/month.

If electricity costs $0.11 per kilowatt-hour, the cost of using these light bulbs for one month would be $0.11/kilowatt-hour * 36 kilowatt-hours/month = $3.96/month.