Please explain how to do units of activity method and declining balance.

Novak Corp. purchased a delivery truck for $35,600 on January 1, 2020. The truck has an expected salvage value of $1,600, and is expected to be driven 100,000 miles over its estimated useful life of 8 years. Actual miles driven were 16,100 in 2020 and 11,700 in 2021.

Compute depreciation expense for 2020 and 2021 using (1) the straight-line method, (2) the units-of-activity method, and (3) the double-declining-balance method. (Round depreciation cost per unit to 2 decimal places, e.g. 0.50 and depreciation rate to 0 decimal places, e.g. 15%. Round final answers to 0 decimal places, e.g. 2,125.)

Depreciation Expense

(1)

Straight-line method

2020:

2021:

(2)

Units-of-activity method

2020:

2021:

(3)

Double-declining-balance method

2020:

2021: