Please show hand calculations!

Nadine Chelesvig has patented her invention. She is offering a patent manufacturer two contracts for the exclusive right to manufacture and market her product. Plan A calls for an immediate single lump payment to her of $35,000. Plan B calls for an annual payment of $800 plus a royalty of $0.50 per unit sold. The remaining life of the patent is 10 years. Nadine uses of 13 %/year. MARR a. What must be the uniform annual sales volume of the product for Nadine to be indifferent between the contracts, based on a present worth analysis? Do all calculations to 5 decimal places and round final answer to a whole number. The tolerance is +/-10 b. If the sales volume is below the volume determined in (a), which contract would the manufacturer prefer