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3) A contractor is considering the following three alternatives: a) Purchase a new computer system for $15,000. The system is expected to last six years with a salvage value of $1,000. b) Lease a computer system for 6 years for $3,000 per year payable at the beginning of each year. c) Purchase a used computer system for $8,200. The system is expected to last 3 years with zero salvage value. Draw cash flow diagrams for each alternative for this problem. For part c., assume that the purchase price of a used computer system will remain the same over the next six years. Which is the best choice using an annual return value of 8%? Which is the best choice for an annual return value of 12%