The reflection of a point A(a, b) across the x-axis, is the point A'(a, -b).
Thus the point P(-1, 6) is reflected to P'(-1, -6).
Check the picture.
Write the equations:

Substitute for h:

Solve for s:

There were 280 downloads of the standard version. There were 1120 downloads of the high-quality version.
If im not mistaken its a 1/8 probability