A stream of air at $30$ Celsius and $101\mathrm{.}3$ kPa containing $2\mathrm{.}8$ mole$\%$ water vapor is fed to a condenser at a rate of $100$ kmol$/$h$.$ The air leaves the condenser with a water vapor content of $0\mathrm{.}8$ mole$\%.$ Calculate:

a$)$ the molar flow rates of the streams leaving the condenser. $(98$ kmol$/$h gas stream and $2$ kmol$/$h liquid stream$)$

b$)$ the temperature at which the condenser operates. $(4$ degree Celcius$)$

c$)$ the relative humidity of the stream fed to the condenser. $(67\%)$