I am learning accounting by myself. But i got some struggles with this exercise.

On July 1, 2011, Company A bought and started to use the following assets: Asset Value Salvage value Useful Life Depreciation method Land $120,000 Not depreciated Land $60,000 10 years Straight line improvements Building $240,000 $100,000 10 years Double declining balance Machinery $180,000 $20,000 10,000 units Units of production Additional information: the machinery is used to produce 700 units in 2011 and 1,800 units in 2012. Required: Compute the depreciation expense for each asset for 2011 (six months) and 2012 - What is the balance of accumulated depreciation and book value for each asset at the end of 2011 and 2012