Energy levels A, B, C of a certain atom correspond to increasing values of energy, i.e.,  ${\mathrm{E}}_A<E_B<E_C$. if ${\lambda }_1,{\lambda }_2,{\lambda }_3$ are the wavelengths of radiation corresponding to the transitions $\mathrm{C}\to B$, $B\to A$ and $\mathrm{C}\to A$ respectively then