A well insulated, thin-walled, double-pipe, counter-flow heat exchanger is to be used to cool oil [Cp = 2.20 kJ/(kg C)] from 150 C to 40 C at a rate of 2 kg/s by water [Cp=4.18 kJ/(kg C)] that enters at 22 C at a rate of 1.5 kg/s. determine the rate of heat transfer in the heat exchanger and the exit temperature of water.