The electricity provider charges $0.09 per kilowatt hour. The light bulb uses 60 watts and is run 24 hours a day. To calculate the cost of running the light bulb we need to calculate how many kilowatt-hours (kWh) of energy the light bulb uses.

60 watts `xx` 24 hrs `-:` 1000 watts/kilowatts = 1.44 kWh

Then we multiply the energy used by the price.

`1.44xx0.09= $0.1296`

This is the price per day.

Now, if we were interested in the price per month, we would multiply by the number of days in the month. So in December, for example, the cost of running the light would be:

`0.1296xx31=$4.0176`

And we can similarly find the cost to run the light bulb continuously for one year:

`0.1296xx365=$47.377`

The energy provider will round your bill to $47.38 per year.