Concept:
The wavenumber of a spectral line in hydrogen spectrum is given by the Rydberg formula:
\[
\bar{\nu}=R\left(\frac{1}{n_1^2}-\frac{1}{n_2^2}\right)
\]
where \(n_2>n_1\).
Step 1: Find the wavenumber of the first Balmer line.
For Balmer series,
\[
n_1=2
\]
The first line corresponds to
\[
n_2=3.
\]
Therefore,
\[
\bar{\nu}_B
=
R\left(\frac14-\frac19\right)
\]
\[
=
R\left(\frac{5}{36}\right).
\]
Step 2: Find the wavenumber of the second Lyman line.
For Lyman series,
\[
n_1=1.
\]
The second line corresponds to
\[
n_2=3.
\]
Hence,
\[
\bar{\nu}_L
=
R\left(1-\frac19\right)
\]
\[
=
R\left(\frac89\right).
\]
Step 3: Calculate the ratio.
\[
\bar{\nu}_B:\bar{\nu}_L
=
\frac{5}{36}:\frac89
\]
\[
=
\frac{5}{36}\times\frac98
\]
\[
=
\frac5{32}.
\]
Therefore,
\[
\boxed{5:32}
\]