The partial pressure of the water vapour in a moist air sample of relative humidity $70\%$ is $1.6 \: kPa$,the total pressure being $101.35 \: kPa$.moist air may be treated as an ideal gas mixture of water vapour and dry air.the relation between saturation temperature ($T_s$ in $K$) and saturation pressure ($p_s$ in $kPa$) for water is given by ln$(p_s/p_o)=14.317-5304/T_s$ where $p_o=101.325 \: kPa$. The dry bulb temperature of the moist air sample (in $_{}^{\circ}\textrm{C}$) is