The demand curve for cigarette is given by Qdx = 46 - 4Px.

a. Sketch the demand function on a graph.

b. What is the quantity demanded and how much buyer surplus do consumers have

when Px = $8? Represent this by means a sketch on the graph.

c. How much buyer surplus do consumers have when Px = $7?

d. Now suppose the seller first sets the price at $8. After all who like to buy the cigarette

have bought the quantity they desire, the seller then unexpectedly lowers the price to $7. What is the total quantity of cigarette sold and what is the consumer surplus? Represent this pricing arrangement on a graph.