Price per foot Jack's demand 3 feet 2 feet $5 $10 $15 $20 feet demanded Moe's demand 4 feet 3 feet 2 feet 1 foot feet Manny's demand 5 feet 4 feet 3 feet 2 feet 1 foot feet O feet 22. Manny, Moe and Jack constitute the market for a retaining wall which is considered to be a public good. The price per foot of the retaining wall and their demand for the retaining wall is described in the table above. If the cost to supply the public good is $30 per foot, what is the efficient quantity of the retaining wall assuming that it is a public good? a Three feet b. Since the government will pay for the public good. 12 feet is optimal because that is what is demanded at a price of zero to Manny, Moe and Jack c Zero because no one is willing and able to pay $30 d. One foot. e. Two feet 23 Manny, Moe and Jack constitute the market for a retaining wall which is considered to be a private good. The price per foot of the retaining wall and their demand for the retaining wall is described in the table above. If the price of the wall is $10 per foot, how many feet of the retaining wall will be built assuming that the retaining wall is a private good? a. 5 feet b. 3 feet C9 feet d. 12 feet e. 6 feet