I would like you to check my answer from (a) to (c) and illustrate (d) with graph.

4 Public Goods [2.5 points] Suppose Alex and Sam both use Wikipedia, a pure public good. Alex's demand for an article on Wikipedia is given by Q = 40-P, and Sam's demand is given by Q = 30-2P. Suppose the marginal cost of producing a Wikipedia article is constant at $35