Online Inc. purchased a machine at a price of $90,000 on January 1, 2028. Online also paid $5,000 for installation and startup costs. Online also incurred some maintenance costs of $10,000 during 2028. Online expects to be able to sell the machine for scrap parts for $15,000 at the end of the useful life. Assume straight-line depreciation for 2028 is $5,000.

What is the useful life of the asset (round to the nearest whole year)?