Period	Cash flow
0	-$70,000
1	$20,000
2	$20,000
3	unknown
4	2500
5	2500

what is the minimum cash flow to find this investment in 3 years? ( using crude payback period, )

assume cash flow for year 3 will be $6,000. what is highest interest rate, not to justify this project? (apply discounted payback method)

What is the advantages and disadvantages of these two payback methods compared to present worth and annual worth methods? When should and can we use this method?