Q$3.($a$)$ Starting from the main KMT equation show that $\sqrt[\phantom{2}]{\frac{?}{\text{b}\text{a}\text{r}}(u{)}^2}=u_x=\sqrt[\phantom{2}]{\frac{3RT}{{}_m}}?$

$($b$)$ It takes gas A $2\mathrm{.}3$ times as long to effuse through an orifice as the same amount of nitrogen. What is the molar mass of gas A$?$