the Speed = Wavelength*Frequency. For example 22*5 = 110 which means the answer would be S = 110mm/s.
Are you sure this question is correct?
If you made a mistake and the question is 20mm/s and 5 freq instead of 22 and 5. Then your answer would be A. 100 mm/s.
Hope this helps! Please mark as brainliest if it did.
