In a single hydrogen atom the electron is excited to 6th orbit. The book says maximum 5 distinct spectral lines are possible when the electron comes to the ground state.
Looks like they have only considered those lines when the electron jumps from shell 6 to ground, shell 5 to ground, shell 4 to ground etc. But in my opinion we should also consider the lines produced while transfer of electrons from 6 shell to 5 shell etc. As the elctron can jump from shell 5 to shell 1 directly only when it has jumped from shell 6 to 5 earlier. That would lead to more number of spectral lines than just 5.
So, am i thinking something wrong here (the word "distinct" seems to be the reason)?