3) a) Construct an interest rate tree according to the method presented in class with step size h = 0.5, volatility = 0.2, drift m = 0.1, and initial 0.5-year rate r = 8%. The tree should give short rates out to time 0.5. b) What is the time 0 price of $1 par of a zero maturing at time 0.5? c) What is the time 0 price of $1 par of a zero maturing at time 1?