Could you solve clearly? Thanks a lot!!

1 July 1, 2010, Studemont purchased a delivery truck for $50,000. The truck has a $10,000 salvage value and a 160,000-mile estimated useful life. Studemont uses the units-of-production depreciation method. Studemont drove the truck 20.000 and 50,000 miles during 2010 and 2011, respectively. What is the balance in Studemont's Accumulated Depreciation account relative to delivery truck at December 31, 2011? a. $ 5,000 b. $12,500 $15,000 $17,500 e. $21,875