Please help. I am lost.

Q3 [50 points] The demand for money is given by I'll" I 5"! [0.15 - D. where 51' = $20,000 {million}. the money supply {M5} is $2000 {million}, and i is the policy interest rate determined by the central bank- a.What is the equilibrium interest rate? Show the equilibrium interest rate on a diagram with money demand and supply curves. b.8uppose that the following year the nominal GDP (5"!) increases from 520.000 to 525.000 (million) and the amount of money in circulation remains unchanged. What would be the new equilibrium interest rate? Show the equilibrium interest rate on a diagram with money demand and supply curves. c. Now suppose that the central bank responds to the change in GDP by $500 {million} increase in money supply. \"that is the impact on the interest rate if central bank money is increased to $2500 {million}? Show the equilibrium interest rate on a diagram with money demand and supply curves