Which of the following expressions represents a simple harmonic progressive wave?

The diagram shows the propagation of a progressive wave. $A$,$B$,$C$,$D$,$E$,and $F$ are points on this wave. Which of the following points are in the same state of vibration (i.e.,in the same phase)?

$A$ progressive wave of frequency $400 \ Hz$ is travelling with velocity $336 \ m/s$. How far apart are the two points on a wave which are $60^{\circ}$ out of phase (in $m$)?

The equation of a progressive wave is $y = 0.2 \sin 2\pi \left[ \frac{t}{0.01} - \frac{x}{0.3} \right]$,where $x$ and $y$ are in meters and $t$ is in seconds. The velocity of propagation of the wave is .... $m/s$.

The equation of a progressive wave is given by $x = 1.2 \sin(314t + 12.56y)$. What are the wavelength and the direction of the wave?

For a progressive wave,$y = 5 \sin (0.01x - 2t)$ (where $x$ and $y$ are in $cm$ and $t$ is in $s$). What will be its speed of propagation (in $cm/s$)?