Suppose that the quantity of corn supplied depends on the price of corn (P) and the amount of rainfall (R). The demand for corn depends on the price of corn and the level of disposable income (I). The equations describing the supply and demand relationships are Q^s=20R+100Pand Q^d=4000100P+10I.

1. Sketch a graph of demand and supply curves (1 marks)
2. Sketch a graph that shows the effect of an increasein rainfall on the equilibrium price and quantity of corn. (2 marks)

Sketch a graph of demand and supply curves that shows the effect of a decreasein disposable income on the equilibrium price and quantity of corn. (2 marks)