A hot-water stream at 80°C enters a mixing chamber with a mass flow rate of 0.46 kg/s where it is mixed with a stream of cold water at 20°C. If it is desired that the mixture leave the chamber at 42°C, determine the mass flow rate of the cold-water stream. Assume all the streams are at a pressure of 250 kPa. The enthalpies are 335.02 kJ/kg, 83.915 kJ/kg, and 175.90 kJ/kg. The saturation temperature at a pressure of 250 kPa is 127.41°C.