Chemical Kinetics

What is the rate of formation of $\mathrm{O}_2$ for the reaction stated below?

$$\begin{aligned} & 2 \mathrm{~N}_2 \mathrm{O}_{5(8)} \longrightarrow 4 \mathrm{NO}_{2(g)}+\mathrm{O}_{2(\mathrm{~g})} \\ & {\left[\frac{\mathrm{d}\left[\mathrm{~N}_2 \mathrm{O}_5\right]}{\mathrm{dt}}=0.02 \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}\right]} \end{aligned}$$