Hello, I only need help with question P12.2

Thank you!!

PROBL E M S P12.1 You have the following information about three electronic sales regis- ters that are in the market. The owner of a restaurant asks for your help in deciding which of the three machines to buy Register A Register B Register C Cash investment required Estimated machine life Estimated residual trade-in value $6,300 $6,000 $6,700 5 years 5 years 5 years at the end of 5 years) 500 400 300 300 Annual operating costs 300 (excluding depreciation) Annual savings before deduction of costs $2,000 $2,000 $2,000 Assume a 30% income tax rate and straight-line depreciation