Two sinusoidal machines are positioned the same distance from a worker . The intensity of sound delivered by each machine at the location of the worker is $\;2.0 \times 10^{-7}\;w/m^2\;$ . Find the sound level heard by the worker (i) when one machine is operating (ii) when both machines are operating

Question

$(a)\;53\;fB\;,37\;fB\qquad(b)\;53\;fB\;,56\;fB\qquad(c)\;53\;fB\;,60\;fB\qquad(d)\;None$