Assuming a competitive market, use demand and supply diagrams to show in each of the following cases

Assuming a competitive market, use demand and supply diagrams to show in each of the following cases how the change in demand or supply for product A creates a disequilibrium consisting of excess demand or excess supply, and how the change in price eliminates the disequilibrium. (a) Consumer income increases (A is a normal good). (b) Consumer income falls (A is an inferior good). (c) There is an increase in labour costs. (d) The price of substitute good B falls. (e) The number of firms in the industry producing product A increases. (f) A successful advertising campaign emphasises the health benefits of product A.