Answer:
a. Depreciation expense = (Cost - Salvage value / Useful life
Depreciation expense = ($225,000 - $25,000) / 10 years
Depreciation expense = $20,000
b. Equipment's net book value = Cost of equipment - Depreciation for 4 years
Equipment's net book value = $225,000 - ($20,000 * 4)
Equipment's net book value = $225,000 - $80,000
Equipment's net book value = $145,000
c. When the sum of undiscounted expected cash flows < Net book value of asset, then the asset is impaired
Here, $125,000 < $145,000. So, the equipment is impaired.
Impairment loss = Net book value of asset - Fair value of asset
Impairment loss = $145,000 - $90,000
Impairment loss = $55,000