At what temperature will the average speed of $CH_4$ molecules have the same value as $O_2$ has at $300 \ K$ ........... $K$

For a gaseous state,if the most probable speed is denoted by $C^*$,average speed by $\overline{C}$,and root mean square speed by $C$,then for a large number of molecules,the ratio of these speeds is:

At $300 \ K$ the average velocity of a gas is $3 \times 10^2 \ cm / s$. The average velocity (in $cm / s$) of it at $1200 \ K$ is

Which of the following equations does not represent the root mean square velocity $(u_{rms})$?

Amongst the following,which should have the highest $rms$ speed at the same temperature?

According to the kinetic molecular theory of gases,the root mean square velocity is proportional to .......