Two sound waves, travelling in same direction can be represented as

${\mathrm{y}}_1=\left(0.02\mathrm{mm}\right)\sin \left[\left(400\pi {\mathrm{rads}}^{-1}\right)\left(\frac{\mathrm{x}}{330{\mathrm{ms}}^{-1}}-\mathrm{t}\right)\right]$ 

and

 ${\mathrm{y}}_2=\left(0.02\mathrm{mm}\right)\sin \left[\left(404\pi {\mathrm{rads}}^{-1}\right)\left(\frac{\mathrm{x}}{330{\mathrm{ms}}^{-1}}-\mathrm{t}\right)\right]$

The wave superimpose.

Distance between two nearest points where an intensity maximum is recorded simultaneously is 165 m.

Distance between two nearest points where an intensity maximum is recorded simultaneously is 330 m.

The time gap between two successive intensity maxima at a given point is 1 sec.

The time gap between two successive intensity maxima at a given point is 0.5 sec.