Compute the payback period for each ofthese two separate investments: a. A new operating system for an existing machine is expected to cost $2?0,000 and have a useful life of six years. The system yields an incremental aftertax income of $??,884 each year after deducting its straightline depreciation. The predicted salvage value of the system is $10,000. b. A machine costs $190,000, has a $14,000 salvage I.ialuer is expected to last ten years, and will generate an aftertax income of $43,000 per year after straight-line depreciation. IlH mama-on