Illustrate each of the following situations with a graph showing the IS curve and the Fed rule, and explain what happens to the equilibrium values of the interest rate and output:
a. A decrease in G with the money supply held constant by the Fed
b. A decrease in G with the Fed changing Ms by enough to keep interest rates constant 

c. A decrease in P with no change in government spending
d. An increase in Z with no change in government spending
e. An increase in P and a decrease in G