A double-pipe, counter flow heat exchanger (co-axial inner and outer tubes with hot fluid flowing through the inner tube and cooling fluid in the outer tube flowing in the opposite direction) is used to cool hot oil (specific heat = 1.9 kJ/kg.K) entering the exchanger at 165oC and 1.8 kg/sec by water (specific heat = 4.2 kJ/kg.K) entering the exchanger at 15oC and 1.2 kg/sec. The cooling water leaves the exchanger at 88oC. a) Calculate the rate of heat exchange between oil and water streams b) Calculate the exit temperature of oil flow.