Answer
a. Highest to lowest in pitch: 660 Hz, 440 Hz, 220 Hz.
b. Highest to lowest in frequency: 660 Hz, 440 Hz, 220 Hz.
c. Highest to lowest in wavelength: 220 Hz, 440 Hz, 660 Hz.
Work Step by Step
a, b. A high frequency corresponds to a high pitch, and the frequencies are given.
c. For waves, the wave speed equals the frequency multiplied by wavelength, so decreasing the frequency means increasing the wavelength. The lowest frequency wave, 220 Hz, has the longest wavelength.