Whenever a hydrogen atom emits a photon in the Balmer series

It must emit another photon in the Lyman series

Since in spectral series of hydrogen atom, Lymen series lies lower Balmer series.

Any transition causing a photon to be emitted in the Balmer series must end at $n=2$. This must be followed by the transition from $n=2$ to $n=1$, emitting a photon of energy $10.2eV$, which corresponds to a wavelength of about $122nm$. This belongs to the Lyman series.