If n₁ and n₂ are the frequencies of sound waves producing beats then the time interval between one maxima and next minima is

Time interval between consecutive maxima, $\mathrm{T}=\frac{1}{\mathrm{Beat} \mathrm{frequency}}=\frac{1}{\left({\mathrm{n}}_1~{\mathrm{n}}_2\right)}$

Time interval between one maxima and next minima will be $\frac{1}{2\left(n_1~n_2\right)}$