Grover Corporation purchased a truck at the beginning of 2017 for $109,200. The truck is estimated to have a salvage value of $4,200 and a useful life of 120,000 miles. It was driven 21,000 miles in 2017 and 29,000 miles in 2018. What is the depreciation expense for 2017? $19,845 $18,375 $25,375 $43,750