Please help?

Question 8 (Challenging). Two flatmates Matt and Ryan are deciding how to best furnish their house. Furniture costs $100 per unit and can be considered both non-excludable and non-rival once purchased. They have the following demand curves: Matt: P = 180 - 15Q Ryan: P = 120 - 10Q a) Solve for the aggregate demand curve b) What is the Samuelson condition for this public good? c) Calculate the surplus for Ryan for the market equilibrium d) Has the Samuelson condition changed? e) Assume that can Ryan continue to free-ride, what is the market equilibrium? How has Ryan's surplus changed? f) Assume that both Ryan and Liam act independently, simultaneously and without knowledge of the other person's provision of furniture. Does this result in the efficient provision furniture? If not calculate the DWL. g) Calculate Ryan's surplus if he pays his Lindahl price. How does this compare with free-riding