A supply of 5 kg/s ammonia at 500 kPa, 20?C is needed. Two sources are available; one is saturated liquid at 20?C, and the other is at 500 kPa, 140?C. Flows from the two sources are fed through valves to an insulated mixing chamber, which then produces the desired output state. Find the two source mass flow rates and the total rate of entropy generation by this setup.