Consider the following reversible reaction :

$A(g)+B(g)2C(g)$

If $1\mathrm{.}0$ mole of $A(g)$ is mixed with $3\mathrm{.}0$ moles of $B(g),$ then $\text{'}x\text{'}$ moles of $C(g)$ are produced at equilibrium. If $2\mathrm{.}0$mol of $A(g)$ is added further at

equilibrium, $\text{'}x\text{'}$ mol of $C(g)$ is further produced at new equilibrium. What is the value of equilibrium constant of the given reaction $?$