\({n_2}\) = Frequency of the siren heard by motorcyclist.
\(v_2\) = Speed of motor cyclist
\(\because\)\({n_1}\) = \(\frac{{330 - v}}{{330 - 22}} \times 176\,\,;\,\,{n_2} = \frac{{330 + v}}{{330}} \times 165\) \({n_1} - {n_2} = 0\)
\(\Rightarrow v = 22 m/s\).