LED bulbs have become more popular in recent years, but do they make financial sense? Suppose a typical 15-watt fluorescent light bulb costs $20 and lasts 12,000 hours. A 8-watt LED bulb, which provides the same light, costs $32 and lasts for 20,000 hours. A kilowatt-hour of electricity costs $0.8. A kilowatt-hour is 1000 watts for 1 hour. If you require a 10 percent return and use a light fixture 1000 hours per year, what is the equivalent annual cost of each light bulb? Which light bulb should you use?