The ratio of mole fraction of A at point P and point Q in following graph is:

 

$P_B^o=100$

$P_A^o=200$

$P_{Total}=P_A^o{x}_A+P_B^o{x}_B$

$=P_B^o+\left(P_A^o+P_B^o\right)x_A$

$140+100+\left(100\right)x_A$

$x_A=0.4=\frac{4}{10}$

$y_A=\frac{P_A^o{x}_A}{P_{Total}}=\frac{200\left(.4\right)}{140}=\frac{80}{140}=\frac{4}{7}$

$\frac{y_A}{x_A}=\frac{\frac{4}{7}}{\frac{4}{10}}=\frac{10}{7}=1.429$