1. A set of tires is purchased for $ 2,800. They last 49,000 kilometers. You drive your car 7,000 kilometers per semester. It must align and balance every 3,500 km. The cost of the service is $ 250 and you can resell the tires at the end of their useful life for $ 300. Other types of tires are maintenance free and last 21,000 km. Its cost is $ 2,000 and it has no recovery when its useful life ends, it must balance every 3,000 km at a cost of $ 225. The interest for case 1 is 8% and for case 2 it is 10%. Which project is better? Solve by VAE (equivalent annual value).

2. A machining service is covered by paying $ 10 for each piece. 2,000 pieces are required per year for 12 years. Another way to do the machining is to acquire a machine that costs $ 5,000 by paying 2 operators who collectively charge $ 4.20 for each part manufactured. In addition to oil with a cost of $ 300 for every 1,000 pieces and $ 400 of electricity for every 500 pieces manufactured. The machine can be sold for $ 1,500 at the end of the plan. The interest rate is 5%. Which project is the best?