Recall the wave equation, [tex]c=f\lambda[/tex] where c is the speed of the wave (m/s), f is the frequency of the wave (Hz) and λ is the wavelength of the wave (m).
[tex]c=f\lambda \Rightarrow \lambda = \frac{c}{f} [/tex] so [tex]\lambda = \frac{3 \times 10^8}{10^{10}} = 0.03 \text{m}[/tex]
