A process fluid having a specific heat of 3500 J/kg-K and flowing at 2 kg/s is to be cooled from 80 C to 50 C with chilled water, which is supplied at a temperature of 15 C and a flow rate of 2.5 kg/s. Assuming an overall heat transfer coefficient of 2000 W/m2-K, calculate the required heat transfer areas for the following exchanger configurations: (a) parallel flow (15 pts), and (b) counterflow (15 pts).