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Question 5 Return air at 25°C and fresh outdoor air at 35°C is mixed in an adiabatic mixing chamber. If 22% of the mixed air is from outdoor air, what is the temperature of the mixed air in °C? A) 28.7 °C B) 22.7 °C C) 27.2 °C Question 6 Air with dry-bulb of 21°C flowing through a duct at 0.55 kg/s is sensibly cooled to 19°C. Assuming that cooling section is insulated and air is cooled using a chilled water, what is the required mass flow rate in kg/s of the chilled water if its allowable temperature rise is 5°C? (A) 0.054 kg/s B) 0.045 kg/s (C) 0.034 kg/s