Given Data:
*The frequency of the sound is:

*The speed of sound in air is:

*The distance between the speakers is:

Step-by-step explanation:
The wavelength of the sound is given by:

Let us consider that we are standing at point P in the figure below.
The path difference will be:

A)
For destructive interference:

B)
When the intensity doubles, the frequency also doubles. So, the wavelength will be:

For constructive interference, path difference is:

Final Answer:
A) The closest distance will be:

B) The closest distance will be:
