(d) For first line in Lyman series $\lambda_{L_{1}} = \frac{4}{3R}$ …(i)
For first line in Balmer series $\lambda_{B_{1}} = \frac{36}{5R}$ …(ii)
From equations (i) and (ii)
$\frac{\lambda_{B_{1}}}{\lambda_{L_{1}}} = \frac{27}{5} \Rightarrow \lambda_{B_{1}} = \frac{27}{5}\lambda_{L_{1}} \Rightarrow \lambda_{B_{1}} = \frac{27}{5}\lambda$