Cold water (cp = 4180 J/kg·°C) enters the tubes of a heat exchanger with 2-shell-passes and 12–tube-passes at 20°C at a rate of 3 kg/s, while hot oil (cp = 2200 J/kg·°C) enters the shell at 130°C at the same mass flow rate. The overall heat transfer coefficient based on the outer surface of the tube is 300 W/m2·°C and the heat transfer surface area on that side is 20 m2. Determine the rate of heat transfer of the heat exchanger.