Ethanol is vaporized at 78C (hfg =846 kJ/kg) in a double-pipe parallel-flow heat exchanger at a rate of 0.03 kg/s, by hot oil (Cp _ 2200 J/kg C) that enters at 120C. If the heat transfer surface area and the overall heat transfer coefficients are 6.2 m2 and 320 W/m2 C, respectively, determine the outlet temperature and the mass flow rate of oil using (a) the LMTD method and (b) the NTU method.