Answer: The frequency of the wave is 0.5 Hz
Step-by-step explanation:
Wave speed is defined as the product of its wavelength and frequency.
Mathematically,

where,
Wave speed of the wave = 6 m/s
= wavelength of the wave = 12 m
= frequency of the wave
Putting values in above equation, we get:

Hence, the frequency of the wave is 0.5 Hz