An equipment for petroleum refining was purchased and placed in service by a large petroleum company. It costs $38000 with a trade in of the old unit which is valued at $12000. The new asset has an estimated MV (market value) of $15000 at the end of an estimated useful life of 16 years. Compute the depreciation amount in eighth year (d8) and the BV at the end of the fourteenth year (BV14) of life using each of the GDS and ADS method.