Compute the payback period for each of these two separate investments: A new operating system for an existing machine is expected to cost $290,000 and have a useful life of six years. The system yields an incremental after-tax income of $83,653 each year after deducting its straight-line depreciation. The predicted salvage value of the system is $11,000. A machine costs $190,000, has a $15,000 salvage value, is expected to last eight years, and will generate an after-tax income of $46,000 per year after straight-line depreciation.

Payback Period
	Choose Numerator:	/	Choose Denominator:	=	Payback Period
		/		=	Payback period
a.				=
b.				=