Water (cp= 4182 J/kg.K) at a flow rate of 5000 kg/hr is heated from 10* C to 35* C in an oil cooler by engine oil (cp = 2072 J/kg.K) with an inlet temperature of 65* C and a flow rate of 6000 kg/hr. Take the overall heat transfer coefficient to be 3500 W/m squared .K. What are the areas required for:
a. Parallel flow
b. Counterflow