Three sound waves of equal amplitudes have frequencies $(n-1),n,(n+1)$. They superimpose to give beats. The number of beats produced per second will be:

1. Superposition of three frequencies $f_1,f_2,f_3$ produces a complex waveform.2. The fundamental beat frequency is the difference between the closest frequencies.3. Difference between $(n)$ and $(n-1)$ is $1$.4. Difference between $(n+1)$ and $(n)$ is $1$.5. The "envelope" of the resulting sound intensity repeat pattern shows a primary beat frequency of $1\text{Hz}$ (the greatest common factor of the differences).(Note: Often $2$ is debated if considering the difference between extremes, but standard beat definition here results in $1$).