If λ1 and λ2 are the wavelengths of the first members of the Lyman and Paschen series, respectively, then λ1 : λ2 is
1 : 3
1 : 30
7 : 50
7 : 108
1λ∝1n12-1n22 ; ∴λ1λ2=132-142paschen112-122Lymen =7/1443/4=7108