An alternative to CFL bulbs and incandescent bulbs are light-emitting diode (LED) bulbs. A 60 W incandescent bulb can be replaced by a 12 W LED bulb. Both produce 800 lumens of light. Assuming the cost of electricity is $0.29 per kilowatt-hour, how much does it cost (in dollars) to run the LED bulb for one year if it runs for four hours a day?

C = $5.08

it costs $5.08 to run the LED bulb for one year if it runs for four hours a day

Explanation:

Given;

Power of Led bulb P = 12 W

Rate r = $0.29 per kilowatt-hour

Time = 4 hours per day

The number of hours used in a year is;

time t = 4 hours per day × 365 days per year

t = 1460 hours

The energy consumption of Led bulb in a year is;

E = Pt

E = 12 W × 1460 hours

E = 17520 watts hour

E = 17.52 kilowatt-hour

The cost of the energy consumption is;

C = E × rate = Er

C = 17.52 × $0.29

C = $5.08

it costs $5.08 to run the LED bulb for one year if it runs for four hours a day