On July 1, 2015, Rex purchases a new automobile for $40,000. He uses the car 80% for business and drives the car as follows: 8,000 miles in 2015, 19,000 miles in 2016, 20,000 miles in 2017, and 15,000 miles in 2018. Determine Rex’s basis in the business portion of the auto as of January 1, 2019, under the following assumptions:

a. Rex uses the automatic mileage method.

b. Rex uses the actual cost method. [Assume that no § 179 expensing is claimed and that 200% declining-balance cost recovery with the half-year convention is used—see Chapter 8. The recovery limitation for an auto placed in service in 2015 is as follows: $3,160 (first year), $5,100 (second year), $3,050 (third year), and $1,875 (fourth year).]