Q$3$: $(10$ Marks$)$

On a particular day, the ambient air was found to have a dry bulb temperature of $30C$ and a wet bulb temperature of $20C.$ The barometric pressure is $9\mathrm{.}69$ m of water. Calculate the following properties without using the psychrometric chart: $($a$)$ Relative humidity, $($b$)$ moisture content, $($c$)$ dew point temperature without using any empirical relations, and$($d$)$ The enthalpy of the air.