Refrigeration and Airconditioning

Moist air at 40°C and 90% R.H. enters a dehumidifier at the rate of 300 m3/min. The condensate and the saturated air exit at 10°C through separate exits. The pressure remains constant at 100 kPa. Determine: (a) the mass flow rate of dry air,
a. 431 kg/min b. 311.61 kg/min c. 278.42 kg/min d. 196 kg/min e. none
(b) the water removal rate, and
a. 11.4 kg/min b. 13.5 kg/min c. 24.2 kg/min d. 19.6 kg/min e. none
(c) the required refrigeration capacity in tons.
a. 221.69 tons b. 310.75 tons c. 181.91 tons d. 257.13 tons e. none

An air-conditioned space is supplied 10 000 ft3/min (283 m3/min) of air at 65°F (18.3°C) and 60% relative humidity. Air is supplied to the dehumidifier at 85°F (29.4°C); wet-bulb temperature is 70°F (21.1°). Condensate leaves the dehumidifier at the same temperature as the outgoing air, which is at standard atmospheric pressure throughout the system. Air leaves the dehumidifier in the same saturated state. Determine the refrigerating load for this air-conditioned space.
a. 28.9 tons b. 39.5 tons c. 48.7 tons d. 51.3 tons e. none


Those are my problems. My professor does not teach us how to solve these kind of problems. I read books, and try to solve, but I did not get the answer. Please show me how to solve these problems.