Consider the following reaction equilibrium

${\mathrm{N}}_2\left(\mathrm{g}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)\rightleftharpoons 2\mathrm{N}{\mathrm{H}}_3\left(\mathrm{g}\right)$

Initially, 1 mole of ${\mathrm{N}}_2$ and 3 moles of ${\mathrm{H}}_2$ are taken in a 2 L flask. At equilibrium state if, the number of moles of ${\mathrm{N}}_{\mathrm{2 }}$is 0.6, what is the total number of moles of all gases present in the flask?