Luric Company purchased a new car on July 1,1999 , for $\$ 15,000$. The estimated life of the car was four years or 104,000 miles, and its salvage value was estimated to be $\$ 2,000$. The car was driven 9,000 miles in 1999 and 27,000 miles in 2000 .

1. Compute the amount of depreciation expense for 1999 and 2000 using the following methods:

a. Straight-line

b. Units-of-production.

2. Which depreciation method reflects more closely the used-up service potential of the car? Explain.