Which one is not correct mathematical equation for Dalton’s Law of partial pressure? Here p = total pressure of gaseous mixture

 ${\text{p}}_{\mathrm{i}}={\mathrm{X}}_{\mathrm{i}}{\mathrm{P}}_{\mathrm{i}}^0$, where   X_i = mole fraction of i^th gas in gaseous mixture
                 ${\mathrm{P}}_{\mathrm{i}}^0=$pressure of i^th gas in pure state

$\mathrm{p}={\mathrm{n}}_1\frac{\mathrm{RT}}{\mathrm{V}}+{\mathrm{n}}_2\frac{\mathrm{RT}}{\mathrm{V}}+{\mathrm{n}}_3\frac{\mathrm{RT}}{\mathrm{V}}$

${\mathrm{p}}_{\mathrm{i}}={\mathrm{X}}_{\mathrm{i}}\mathrm{p}$, where p_i = partial pressure of i^th gas
                                X_i = mole fraction of i^th gas in gaseous mixture

$\mathrm{p}={\mathrm{p}}_1+{\mathrm{p}}_2+{\mathrm{p}}_3$