Awave has a wavelength of 10mm and a frequency of 5 hertz what is the speed

Wavelength, frequency and speed can be related in the following equation
λf = v
where λ - wavelength (m)- the distance from one point of the wave to the same point on the next wave
           f - frequency of wave (Hz), Hz is number of waves per second 
           v - speed - ms⁻¹
substituting the values 
10 x 10⁻³ m x 5 s⁻¹ = 0.05 ms⁻¹
speed of the wave is distance the wave can travel within a second.