Speed of Ocean Waves: 900m/min?

[roam]

Homework Statement

Ocean waves with a wavelength of 120 m are coming in at a rate of 8 per minute. What is their speed?

The Attempt at a Solution

\lambda = 120

They are coming in at a rate of 8 per minute, that is 8 in 60 seconds. So the period is

T=\frac{8}{60}=0.13

Now we find frequency

f=\frac{1}{T}=\frac{1}{0.13}=7.5

v=f \lambda = 120 \times 7.5=900

But this is wrong. It is far larger than the actual answer! What did I do wrong?

 

[rock.freak667]

8 per minute would be the frequency, not the periodic time I believe.