Final answer:
The balance in Accumulated Depreciation on December 31, 2017, using the double-declining-balance method is $76,800.
Step-by-step explanation:
To calculate the balance in Accumulated Depreciation using the double-declining-balance method, we need to determine the depreciation expense for each year.
The formula for double-declining-balance method is: (Cost - Accumulated Depreciation) x (2 / Useful Life).
For the given equipment, the cost is $120,000, the useful life is 5 years, and the residual value is $20,000. The depreciation rate is (2 / 5) = 0.4.
In the first year, the depreciation expense would be: ($120,000 - $0) x 0.4 = $48,000. The accumulated depreciation after the first year would be $48,000.
In the second year, the depreciation expense would be: ($120,000 - $48,000) x 0.4 = $28,800. The accumulated depreciation after the second year would be $48,000 + $28,800 = $76,800.
Therefore, the balance in Accumulated Depreciation on December 31, 2017, would be $76,800.