Answer:
f = 1.5 Hz
Explanation:
Given that,
18 waves pass by a person in 12 seconds.
We need to find the frequency of these water waves.
We know that,
Frequency = no. of waves per second
So,
[tex]f=\dfrac{18}{12}\\\\f=1.5\ Hz[/tex]
So, the frequency of these water waves is equal to 1.5 Hz.