As we know so far, c = f / λ. This equation comes from a much simpler version of speed = distance/ time. As the λ (with units "m") can be seen as distance and the frequency (with units "1/s") can be seen as time. So by substituting the wave measurements into the speed = distance/ time formula, you can understand the c = f / λ equation a lot better.
Now lets make f= 500 Hz and λ = 0.34
So c= 500/ 0.34
Therefore c = 170 (m/s)