What happens to the price and quantity of hamburgers if the demand for hamburgers increases and the supply of hamburgers increases?

If the price of the substitute good (hot dogs) rises, so will the demand for hamburgers, and if the price of the complement good (hamburger buns) rises, so will the desire for hamburgers, therefore the resulting shift in demand is impossible to predict.

Demand for hamburgers rises when the price of a substitute good (such as hot dogs) rises. This is evident by the fact that buyers purchase substitute goods at a lower cost. When the price of one good rises, so does the demand for all the others. The demand curve will shift rightward from D1 to D2 as a result of the desire for hamburgers, as seen in the graph.

Demand for hamburgers reduces whenever the price of a related commodity (such as hamburger buns) rises. This really is the case since complementary items are consumed together.

As a result, if the price of hamburger buns rises, the demand for hamburger buns will fall, and hence the demand for hamburgers will fall as well. The desire for hamburgers will cause the demand curve to shift downward from D1 to D3, as seen in the graph. We can't predict whether or not a demand for hamburgers will rise or fall which is not clear.

a) The price of tacos increases. Assume that tacos are a substitute for hamburgers. In this case the demand for hamburgers will increase, the equilibrium price will increase, the equilibrium quantity will increase.

b) All hamburger sellers raise the price of soda. Assume that soda is a complement of hamburgers.

In this case the demand for hamburgers will decrease, the equilibrium price will decrease, the equilibrium quantity will decrease.

c) Income falls. Assume that hamburgers are a normal good.

In this case the demand for hamburgers will decrease, the equilibrium price will decrease, the equilibrium quantity will decrease.

d) Income falls. Assume that hamburgers are an inferior good.

In this case the demand for hamburgers will increase, the equilibrium price will increase, the equilibrium quantity will increase.

e) Hot dog stands cut the price of hot dogs. Assume that hot dogs are a substitute for hamburgers. In this case the demand for hamburgers will decrease, the equilibrium price will decrease, the equilibrium quantity will decrease.