The first line in the Lyman series has wavelength λ. The wavelength of the first line in Balmer series is
29λ
92λ
527λ
275λ
For first line in Lyman series λL1=43R…….(i)
For first line in Balmer series, λB1=365R……(ii)
From equations (i) and (ii),
λB1λL1=275 ⇒λB1=275λL1 Thus, λB1=275λ