Please show all work! Isentropic Flow Problems

3. A rocket nozzle has an exit-to-throat area ratio of 4.0 and a throat area of 100 cm2. The exhaust gases are generated in a combustion chamber with stagnation pressure equal to 4 MPa and stagnation temperature equal to 2000 K. Assume the working fluid to behave as a perfect gas with k=1.3 and molar mass = 20 kg/kmol. Determine (a) the rocket exhaust Mach number and velocity and (b) the mass flow rate. Assume isentropic steady flow