Ratio of wavelengths  of series limit in Lyman, Balmer and Paschen series in Hydrogen spectrum.

for series limitn2 = ∞    n1 = 1.....Lymann1 = 2....Balmern1 = 3....PaschenLyman=RH112−1∞2 = ν−Balmer=RH122−1∞2 = ν−Paschen=RH132−1∞2 = ν−Wavenumber ratio1 :  14: 19Wavelength ratio1:4:9