Show all the calculations precisely and clearly!

1. (10 Marks) Determine the economic life for each of the items listed in the box. Salvage values can be estimated by the declining-balance method using an annual rate of 20 percent. The MARR is 8 percent. Purchase Installation Operating Item 1 $10 000 $2000 $300 first year, increasing by $300 per year Item 2 $20 000 $2000 $200 first year, increasing by $200 per year Item 3 $30 000 $3000 $2000 first year, increasing by $2000 per year