As we know that when two sound sources of slightly different frequency sound together then we will have resultant sound intensity changes with time
this is known as Beats
in order to find the beat frequency we will use
[tex]f_{beat} = f_1 - f_2[/tex]
here we know that
[tex]f_1 = 882 Hz[/tex]
[tex]f_2 = 880 Hz[/tex]
now here we know that from above formula
[tex]f_{beat} = 882 - 880 = 2Hz[/tex]
now from this equation we can say that we will hear 2 beats per second
so time interval between two beats is given as
[tex]T = \frac{1}{f_{beat}}[/tex]
[tex]T = \frac{1}{2} = 0.5 seconds[/tex]