A Hot water stream at 80o C enters a mixing chamber with a mass flow of 0.5 Kg/s where it is mixed with a stream of cold water at 20o C. If it is desired that the mixture leave the chamber at 42oC, determine the mass flow rate of the cold-water stream. Assume all the streams are at a pressure of 250 KPa.How do you work it out. The answer is 0.865 Kg/s