Polly and Paul are the only two consumers of a public park in the economy of Econoland.Polly's demand function for this public park is Qdpo= 20 - 0.2P while Paul's demand function for this public park is Qdpa= 20 - 0.1P where Q is in acres and P is in dollars per acres.The supply function for this public park is Qs= 0.2P.

a.) The aggregate/market demand function for this public park in Econoland is_______________

b.) The marginal willingness-to-pay function for this public park in Econoland is________________

c.) The 'shadow' price of this public park is equal to__________

d.)The socially efficient size of this public park is_________

e.)At the socially efficient size for this public park , Polly's marginal willingness-to-pay for the last acre is equal to________