Cho hình lăng trụ ABC.A'B'C' Gọi M, N lần lượt là trung điểm của AA’, BB’

* Hướng dẫn giải

Đáp án A

$\begin{array}{l}{V}_{AA\text{'}B\text{'}C\text{'}}=V_{C\text{'}ABC}=V_{ABB\text{'}C\text{'}}\\ =\frac{1}{3}{V}_{ABCA\text{'}B\text{'}C\text{'}}\\ V_{MNA\text{'}B\text{'}C\text{'}}=\frac{1}{2}{V}_{C\text{'}ABB\text{'}A\text{'}}\\ =\frac{1}{2}.(V_{AA\text{'}B\text{'}C\text{'}}+V_{ABB\text{'}C\text{'}})\\ =\frac{1}{2}.\frac{2}{3}{V}_{ABCA\text{'}B\text{'}C\text{'}}=\frac{1}{3}{V}_{ABCA\text{'}B\text{'}C\text{'}}\\ \Rightarrow \frac{V_{MNC\text{'}ABC}}{V_{MNA\text{'}B\text{'}C\text{'}}}=2\end{array}$