An alternative to CFL bulbs and incandescent bulbs are light-emitting diode (LED) bulbs. A 100 W incandescent bulb can be replaced by a 16 W LED bulb. Both produce 1,600 lumens of light. Assuming the cost of electricity is $0.20 per kilowatt-hour, how much does it cost (in dollars) to run the LED bulb for one year if it runs for three hours a day

cost to run the LED bulb for one year if it runs for 3 hours a day is $3.50

Explanation:

given data

power = 16 W

cost of electricity = $0.20 per kilowatt-hour

time = 3 hours a day.

solution

we get here energy consumption is express as

E = Power * time

E = (16) * (365 * 3)

E = 17520 Wh

E = 17.52 kWh

and

cost of operation = E * cost of electricity ... 1

cost of operation = 17.52 * $0.20

cost of operation = $3.50

so cost to run the LED bulb for one year if it runs for 3 hours a day is $3.50