Equation of two waves are

$y = A \sin(wt - kx)$

$y=A \sin(wt - kx + 90)$ 90 denotes 90 degrees,

A is amplitude,w is angular frequency, $k$ is wave number;

Now the equation of the resulting wave can be represented as

$y = A\sqrt [ 2 ]{ a } \sin(wt - kx + b)$
where $a$ is an integer, and $b$ is in degrees

Find $(b*2)/(a*5)$.