Details solving pls

(c) (4 points) Assume the money demand function is described by: MP = 0.5Y - 5i. Calculate the equilibrium interest rate if income is 100 and money supply 20? (d) (4 points) Explain what is meant by a "liquidity trap". (e) (10 points) Show graphically and explain using an IS-LM model with a money targeting central bank the implications of a fiscal expansion. What are the effects on the interest rate, output, consumption and investment