For a gaseous phase reaction _{${\text{A}}_{\left(\text{g}\right)}{\text{+3B}}_{(\text{g)}}\rightleftharpoons {\text{2C}}_{\left(\text{g}\right)}$} , initial pressure is 600 mm at $\text{1}:\text{ 2}$ molar ratio of A and B. If the equilibrium pressure of A is 100mm, that of B & C respectively are (in mm)

$A+3B\rightleftharpoons 2C$

$200$              $400$                 $0$

$(200-x)$ $(400-3x)$       $2x$

Given that

$200-x=100$

           $x=100$

Initial pressure of $A=\frac{1}{3}\times 600=200mm$

Initial pressure of $B=\frac{2}{3}\times 600=400mm$

$\therefore$  Eq. pressure of $C=2x=200mm$

$\therefore$  Eq. pressure of $B=400-3x=100mm$