Equipment with a cost of R.0.320,000 has an estimated residual value of R.O.20,000 and an estimated life of 4 years or 15,000 hours. It is to be depreciated using the units-of-activity method. During the first year the equipment was used 3,300 hours; what is the equipment book value at the end of the first year? Select one: a. R.O.254.000 b.R.O.300,000 OCR.O.249,600 O d.R.O.320,000