Consider a complex reaction taking place in three steps with rate constants k_1, k_2 and k_3 respectively. The overall rate constant k is given by…

Consider a complex reaction taking place in three steps with rate constants $\displaystyle \mathrm{k}_1, \mathrm{k}_2$ and $\displaystyle \mathrm{k}_3$ respectively. The overall rate constant k is given by the expression $\displaystyle \mathrm{k}=\sqrt{\frac{\mathrm{k}_1 \mathrm{k}_3}{\mathrm{k}_2}}$. If the activation energies of the three steps are $\displaystyle 60$, $\displaystyle 30$ and $\displaystyle 10 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively, then the overall energy of activation in $\displaystyle \mathrm{kJ} \mathrm{mol}^{-1}$ is $\displaystyle \_\_\_\_$. (Nearest integer)