Ta có: \(\frac{{{V_{S.AMN}}}}{{{V_{S.ABC}}}} = \frac{{SM}}{{SB}}.\frac{{SN}}{{SC}} = \frac{1}{2}.\frac{2}{3} = \frac{1}{3}\) và \({V_{S.AMN}} + {V_{A.BMNC}} = {V_{S.ABC}}\)

⇒ \(\frac{{{V_{A.BMNC}}}}{{{V_{S.AMN}}}} = \frac{{{V_1}}}{{{V_2}}} = 2.\)