Holt Developments Ltd. put an asset in service on January 1, 2018. Its cost was $180,000, its predicted service life was six years, and its expected residual value was $18,000. The company decided to use double-declining balance depreciation. After consulting with the company's auditors, management decided to change to straight-line depreciation in 2020, without changing either the original service life or residual value Required: a. What is depreciation expense for 2020? Depreciation expense