A light burns out in your house, so you go to the store to buy a replacement. You can spend $22 to buy an equivalent LED bulb, spend $2 to buy a 60-watt incandescent light bulb, which only uses 12 W however is just as bright. On average, the bulb will be on for 4 hours per day, and the power company charges you $0.20 per kW-hr of energy you use.
(a) If you buy the more expensive LED bulb, how long (in days) will it be before you break even? In other words, how long will it take before the combined purchase cost + energy cost is the same for these two bulbs?