c
\(x \) ના મોલ-અંશ \({X_A} = \frac{1}{{1 + 3}} = \frac{1}{4};\,\)

\(y  \) ના મોલ- અંશ \({X_B} = \frac{3}{{1 + 3}} = \frac{3}{4}\)

\({\text{P}}\) કુલ \({\text{ =  }}{{\text{p}}_{\text{A}}}^{\text{0}}{{\text{X}}_{\text{A}}}{\text{  +  }}{{\text{p}}_{\text{B}}}^{\text{0}}{{\text{X}}_{\text{B}}}\,\)

\( \Rightarrow \,\,\,{\text{P}}\) કુલ \( = \frac{{{P_A}^0}}{4} + \frac{{{P_B}^0}}{5}\)

\(\therefore \,\,550 = \frac{{{p_A}^0 + 3p{B^0}}}{4}\,\,\,\)

\(\therefore \,\,\,{{P}^{0}}_{A}\text{+ 3}{{\text{p}}_{\text{B}}}^{\text{0}}\text{  =  550 }\times \,\,\text{4}\,\text{=}\,\text{2200}\) ............... \((1)\)

\(y \) નો \(1 \)  મોલ ઉમેરતા,  \(\,{\text{P}}\) કુલ \({\text{ =  }}{{\text{p}}_{\text{A}}}^{\text{0}}{{\text{X}}_{\text{A}}}{\text{  +  }}{{\text{p}}_{\text{B}}}^{\text{0}}{{\text{X}}_{\text{B}}}\,\)

\(\therefore 560 = \frac{{{P_A}^0}}{5} + \frac{{4{p_B}^0}}{5}\)

\({X_A} = \frac{1}{{1 + 4}} = \frac{1}{5},\,\,\,\,\,\,{X_B} = \frac{4}{{1 + 4}} = \frac{4}{5}\)

\(\therefore {\text{ }}{{\text{p}}_{\text{A}}}^{\text{0}}{\text{  +  4}}{{\text{p}}_{\text{B}}}^{\text{0}}{\text{  =  560 }} \times {\text{ 5}}\,\,\)

\(\therefore \text{  }{{\text{p}}_{\text{A}}}^{\text{0}}\text{+ 4}-{{\text{p}}_{\text{B}}}^{\text{0}}\,\text{=}\,\,\text{2800}\)   .............................. \((2)\)

પરિણામ \((2)\)  - પરિણામ \( (1)\)  કરતાં

\(\therefore \,\,{{\text{p}}_{\text{A}}}^0 + 4{p_B}^0\, - \,{p_A}^0 - 3{p_B}^0 = 2800 - 2200\)

\(\therefore {\text{  }}{{\text{p}}_{\text{B}}}^{\text{0}}{\text{  =  600}}\) મિમી

\({\text{ }}\therefore {\text{ }}{{\text{p}}_{\text{A}}}^{\text{0}}{\text{  =  400 }}\) મિમી