A new market has emerged for Internet of Tea Makers. We'll need to ship the Internet of Tea Makers to the new market. To do this we can buy a truck second hand. The truck costs $50,000 as-is. Maintenance costs for the first year are $2,500 and the maintenance cost is expected to increase by $500 per year after that. Operating costs are expected to be $8,000 per year. The resale value of our truck will decrease by 20% per year. If interest rates are 3% what is the economic life of the truck?