1.
Answer:

Step-by-step explanation:
Initially the two sound producing speakers are in same phase.
so here the distance between them must be equal to the half of the wavelength.
So here we will have

speed of sound wave

now we have


now the distance between two sources for destructive interference will be given as

2.
Answer:

Step-by-step explanation:
Initially the two sound producing speakers are out of phase.
so here the distance between them must be equal to the half of the wavelength for producing constructive interference.
So here we will have

speed of sound wave

now we have


now the distance between two sources for constructive interference will be given as
