When two sound waves travel in the same direction in a medium, the displacement of a particle located at $\mathrm{x}$ at time $\mathrm{t}$ is given by $\mathrm{y}_{1}=0.05 \cos (0.50 \mathrm{p} \mathrm{x}-100 \mathrm{pt}) \&$
$y_{2}=0.05 \cos (0.46 p x-92 p t)$, where $y_{1}, y_{2}$ and $x$ are in meter and $t$ is in seconds.
How many times per second does an observer hear the sound of maximum intensity ?
(A) 4
(B) 8
(C) 12
(D) 16