How Many Hydrogen Atoms Minimum for All Emission Spectra from n=5?

[sid94]

Not sure how to go ahead with this problem:

Hydrogen atoms in a sample are excited to n=5 states and it is found that photons of all possible wavelengths are present in the emission spectra. What would be the minimum no. of hydrogen atoms in the sample?

(sorry got nothin buzzin to attempt this problem.. so please help out!)

Thnxx

 

[ap123]

Think of all the different ways an atom in n=5 can decay back to the ground state.