13. Consider the following:

a. Regent Corp. bought a machine costing $22,400 on January 1, 2020. A six-year life was estimated, and a $1,400 residual value was expected. The sum-of-the-years'-digits depreciation method was used. Compute depreciation expense for 2024. $___________

b. The company bought a machine costing $50,000 on January 1, 2020. A six-year life was expected, and residual value was estimated to be $8,000. The 150%-declining-balance depreciation method was used. Compute depreciation expense for 2021. $__________

1. Which of the following is not considered involuntary disposal?

   earthquake

   exchange

   expropriation by the government

   fire