Swifty Corporation purchased a truck at the beginning of 2020 for $109600. The truck is estimated to have a salvage value of $4100 and a useful life of 123000 miles. It was driven 18000 miles in 2020 and 26000 miles in 2021. What is the depreciation expense for 2020?
a. $37752
b. $22308
c. $16639
d. $15444