The lights used at the local baseball stadium cost $125 per bulb. Of the 120 bulbs at the stadium, 20 will fail after 2400 hours, 80 will fail after 2800 hours, and the remaining bulbs will fail after 3600 hours. The labor cost to replace individual bulbs is $150 per bulb. If the bulbs are replaced in bulk, the labor cost is $85 per bulb. The stadium hosts 120 games and events each year. The average time the lights are in use for each event is 5 hours. Compare the cost of individual replacement with block replacement at 2400 hours using i = 12%