In an excited state an electron in a hydrogen atom can return to the ground state in two different ways: first, through the direct transition in which a photon of wavelength λ1 and second, through the intermediate excited state which is reached by the emission of a photon of wavelength λ2. This intermediate excited state then decays to the ground state by emitting another photon of wavelength λ3. Obtain an equation that relates λ1 tp λ2 andλ3.