\rho_t = \frac{\dot m}{q_t} = (\frac{\dot m_O + \dot m_G + \dot m_G)/ \left(}{
\frac{B_o - B_g \, R_v}{1-R_v \, R_s } \cdot \frac{\dot m_O }{\rho_O}
+\frac{B_g - B_o \, R_v}{1-R_v \, R_s } \cdot \frac{\dot m_G }{\rho_G}
+ B_w\cdot \frac{\dot m_W}{\rho_W}
\right)^{-1} |