The velocity of the wave is equal to 3.6 meters per second.
The speed of any wave is the product of the wavelength and the frequency.Since your units are the standard SI units (meters, and hertz, which is equal to 1/seconds), the product will be in meters/second.
0.3 m/s
speed = wavelength x frequency
frequency = 1/s = Hz
speed = 0.2 m x 1.5/s = 0.3 m/s
It is 0.3 metres/second.
3.6 m/s
APEX