What is the maximum number of emission lines when the excited electron of a H atom in `n = 6` drop to the ground state?

Explanation

The maximum no. of emission lines `=(n(n-1))/(2)=(6(6-1))/(2)=3xx5=15`.
The actual transitions which are taking place are as follows :
`{:(n=6" to "n=1,,n=5 " to "n=1,,n=4 " to " n=1,,n=3 " to "n=1,,n=2 " to "n=1),(" "6to5,," "5to4,," "4to3,," "3to2,," "2to1),(" "6to4,," "5to3,," "4to2,," "3to1,,),(" "6to3,," "5to2,," "4to1,,,,),(" "6to2,," "5to1,,,,,,),(" "6to1,,,,,,,,),(" "(5" lines"),," "(4" lines"),," " (3 " lines"),," "(2" lines"),," " (1" lines")):}`