The ratio of the wave lengths of the first line in the Lyman series of the spectrum of Hydrogen atom and the first line in the Balmer series of the spectrum of He+ is

Ratio= 27/5

This is the direct result of formula which can be easily calculated by putting n1 = 1 & n2 = 2 in case of Lymann Series and n1 =1 & n2 = 3 in case of Balmer Series .