A cubical box $1\mathrm{.}05$ mm on a side contains air at $20\mathrm{.}0$C$$C$.$ What would the pressure inside the box have to be in order for the mean free path of air molecules $($assumed to be spheres of radius $2\mathrm{.}01010$m$2\mathrm{.}01010$m$)$ to be $1\mathrm{.}05$ mm$,$ so that a typical molecule suffers no collisions with other molecules as it travels the width of the box?