Gas A taken in a closed rigid container is allowed to decompose Partially according to the reaction. 

$A\left(g\right)⟶2B\left(g\right)+3C\left(g\right)$

The gaseous mixture formed effuses 1.5 times faster than a gas having molecular weight 105 under similar conditions. Find the mole fraction of C in the gaseous mixture formed. 

Given:   $\text{ Mol. wt. }$ of $A=140$

               $\text{ Mol. wt. }$ of $B=64$

              $\text{ Mol. wt. }$ of $C=4$