An asset with a first cost of $100,000 is depreciated over 5-year period. It is expected to have a $10,000 salvage value at the end of 5 years.

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

(2) Using the sum of years digit method, what is the depreciation expense for year 1?

(3) Using the doubledeclining balance method, what is the depreciation expense for year 3?