In a container ${\mathrm{H}}_2\mathrm{O}\left(g\right),\mathrm{CO}\left(g\right)$and ${\mathrm{H}}_2\left(g\right)$ are present in the molar ratio of 1 : 2 : 3 respectively at temperature of 300 K. Find the pressure in the container at which solid carbon (graphite) will start forming in the container, given that:

$\mathrm{C}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\rightleftharpoons \mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)K_P=3\mathrm{atm}$.