The mixture, which has an average heat capacity of 3.0 kJ/kg.K and flows through the inner pipe at a speed of 7300 kg/hour, is wanted to be cooled from 102 C to 39 C in a double-pipe heat exchanger. Water entering at 16 C is used for cooling and the mass flow rate of water is 4600 kg/hour. Since it is known that the overall heat transfer coefficient is U: 850 W/msquare.K, calculate the heat exchanger area for the heat exchangers given below. a) parallel flow b) counter current (cp, water: 1 cal/g.C)