${\mathrm{NO}}_2$ required for a reaction is produced by decomposition of ${\mathrm{N}}_2{\mathrm{O}}_5$ in ${\mathrm{CCl}}_4$ as by equation $2{\mathrm{N}}_2{\mathrm{O}}_{5( \mathrm{g})}\to 4{\mathrm{NO}}_{2( \mathrm{g})}+{\mathrm{O}}_{2( \mathrm{g})}$
The initial concentration of ${\mathrm{N}}_2{\mathrm{O}}_5$ is $3 \mathrm{mol} {\mathrm{L}}^{-1}$ and it is $2.75 \mathrm{mol} {\mathrm{L}}^{-1}$ after $30$ minutes.
The rate of formation of ${\mathrm{NO}}_2$ is $\mathrm{x}\times {10}^{-3} \mathrm{mol} {\mathrm{L}}^{-1}$ $\min -1$, value of $\mathrm{x}$ is ________.

Hence, the correct answer is 17.