The cooling tower in Fig. 7 receives 6 kg/s of water of 60 °C. Air enters the tower at 32 °C dry bulb and 27 °C wet bulb temperatures and leaves at 50 °C and 90% relative humidity. The cooling efficiency is 60.6%. Determine:

(a) the mass flow rate of air entering, and

(b) the quantity of make-up water required.