A machine purchased for $$45,000$ has a depreciable life four years. It will have an

expected salvage value of $$5000$ at the end of the depreciable life.

$($a$)$ Using the straight$-$line method, what is the book value at the end of year $2?$

$($b$)$ If the double$-$declining balance $(200\%$ DB$)$ method is used, what is the depreciation amount

for year $2?$