What is the ratio of wavelength λ₁/λ₂ in the given figure of energy levels of a molecule

6 : 1

$ \lambda = \frac{hc}{\Delta E} $

$ \lambda_1 = \frac{hc}{-E-(-5E/3)} = \frac{hc}{2E/3} = \frac{3hc}{2E}$

$ \lambda_2 = \frac{hc}{-E-(-5E)} = \frac{hc}{4E} = \frac{hc}{4E}$

$\frac{\lambda_1}{\lambda_2} = \frac{\frac{3hc}{2E}}{\frac{hc}{4E}}= 6:1$