1. It is estimated that a bulb will get an average use of 3 hours per day => ~1000 hours per year, so we will
base our calculations on 1000 hours of use. Each of these light bulbs are rated to give off the same
amount of brightness ~ 800 lumen. The cost of electricity in Southern California is 32 cents per kWh.
a. Use a 60 W incandescent bulb, costing 5 cents that has a lifespan of 1000 hours, what is the total
cost (capital plus operation) for 1000 hours of use?
b. Use a 13 W compact fluorescent light (CFL), costing $5.50 that has a lifespan of 10,000 hours,
what is the total cost for 1000 hours of use?
c. Use an 8.8 W LED light, costing $3.50 that has a lifespan of 15,000 hours, what is the total cost
for 1000 hours of use?