Answer:
Depreciation Expense for December 31, 2016 = $12000
Explanation:
1st normal Depreciation in order get book value on January 1st, 2016
Depreciation Expense = (Cost - Salvage value ) / Estimated useful life
Depreciation Expense = ($60000-$24000) / 6
Depreciation Expense = $6000
As it straight line method depreciation will remain same So value of Truck will reduce by $12000. Hence, book value of Truck will be ($60000 - $12000) = $48000
Now get new book value by adding current book value of Truck and repairs on truck. ($48000 + $20000) = $68000 and new salvage value is $8000.
New Depreciation expense:
Depreciation Expense = (Cost - Salvage value ) / Estimated useful life
Depreciation Expense = ($68000-$8000) / 5
Depreciation Expense = $12000