assume there are no lights in place at time 0. So you must decide and incur a cost today (at time 0) so that the building has lighting starting at time 0. The bulbs should last until the end of the period (e.g., LEDs last until the end of year 15, and needs to be replaced at the beginning of year 16).

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Vanke (SEHK:2202) is one of the largest owners and managers of Class A office spaces in the growing innovation hubs of Shenzhen. Project manager Natalie Yang is in the midst of overseeing renovations of Vanke's Horizontal Skyscraper. Among the long lists of upgrades Natalie has specified, modern recessed lighting throughout the property is sure to be a huge hit. All the fixtures have already been installed. Natalie just has to decide between halogen or LED bulbs. Natalie estimates that installing halogen bulbs would cost roughly $5 per bulb while LED bulbs would be substantially more costly at roughly $30 per bulb. The Horizontal Skyscraper is 128,000 square meters and has 1 recessed light for every 16 square meter, so the total increase in cost from using LEDs is $200,000, a large amount given this is just for light bulbs. However, Natalie thinks the extra costs might just be worth it because LED bulbs last nearly 16 times as long as halogens. Your task is to help Natalie use the concept of Net Present Value to decide which type of bulb to use. Use the following assumptions: . Halogenbulb expected lamp life: 3000 hours LED bulb expected lamp life: 48,000 hours Lights operate: 12 hurs a day 250 Days a year . Haloge ulb price stays constant for foreseeable future After 16 years, the light fixtures will be replaced, i.e., no need to include n your calcula- tions anything that happens after year 16 Interest Rate: 5% Questions 1. What type of light bulb should Natalie Choose? 2. What are the cost savings (in present value ters) of your recommendations relative to the alternative? 3. What type of light bulb should Natalie choose if the interest rate is 15%