Zahid Company squired machinery on January 1, 2017 without $52.000. The useful life of the machinery is expected to be 5 year. The vape value at the end of the life of the machinery expected to be $2,000. The machinery can produce maximum 20,000 units during its useful life. 

Required 

a. Calculate depreciation in 2015 using straight line depreciation method. 

b. Calculate depreciation in 2017 using units of production method 5,000 units are produced in 2017. 

c. Records journal entry for depreciation in 2017 using double declining balance method.