A certain dog whistle operates at 23.5 kHz, while another
Chapter 12, Problem 47(choose chapter or problem)
A certain dog whistle operates at 23.5 kHz, while another (brand X) operates at an unknown frequency. If humans can hear neither whistle when played separately, but a shrill whine of frequency 5000 Hz occurs when they are played simultaneously, estimate the operating frequency of brand X.
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