Áp dụng quy tắc đường chéo ta có
\(\frac{0,6-C_{M\left(C\right)}}{C_{M\left(C\right)}-0,2}=\frac{2}{3}\)
\(\Rightarrow1,8-3C_{M\left(C\right)}=2C_{M\left(C\right)}-0,4\)
\(\Rightarrow5C_{M\left(C\right)}=1,4\)
\(\Rightarrow C_{M\left(C\right)}=\frac{2,2}{5}=0,44\left(M\right)\)