A workshop intends to update an old hexagonal lathe with a CNC lathe (assuming that the residual value of the old lathe is zero). The price of a new lathe is 80 000 After the equipment is updated, the depreciation fee will increase by 8 000 yuan per year. It is estimated that the after-tax profit after the update will increase by RMB 12,000 per year. (1) What is the annual net cash benefit after tax? (2) Assuming that the net cash benefits remain unchanged within 5 years, and also assuming that the residual value of the new machine at the end of the fifth year is RMB 40,000, the companys capital The gold cost is 15%, is it cost-effective to update the lathe? Total present value coefficient (15%, 5)=3.352; present value coefficient (15%, 5)=0.497