An unknown compound A dissociates at \[500{}^\circ \,C\] to give products as follows \[\underset{(g)}{\mathop{A}}\,\,\,\,\rightleftharpoons \,\,\,\underset{(g)}{\mathop{B}}\,\,\,\,\,+\,\,\,\,\,\underset{(g)}{\mathop{C}}\,\,\,\,\,\,\,+\,\,\,\,\underset{(g)}{\mathop{D}}\,\] vapour density of the equilibrium mixture is 50 it dissociate to the extent of \[10\,%\]. What will be the molecular weight of compound A