Consider a complex reaction taking place in three steps with rate...

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 the expression $k=\sqrt{\frac{k_1 k_3}{k_2}}$. If the activation energies of the three steps are 60,30 and $10 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}$ respectively, then the overall energy of activation in $\mathrm{kJ} \mathrm{mol}^{-1}$ is $\ldots\ldots$ . (Nearest integer)