Q$4$: $(14$ Marks$)$

$15\frac{m^3}{s}$ of air at $35C($DBT$)$ and $24C($WBT$)$ and an atmospheric pressure of $101\mathrm{.}325$ kPa enters an air washer and the air leaves saturated at $31C($a$)$ to what temperature can this airstream cool a spray of water entering at $38C$ with a flow rate of $20k\frac{g}{s}$ and $($b$)$ how many kilograms per second of make$-$up water must be added to compensate for the water that is evaporated?.