You have not provided the diagram/coordinates for point Q, therefore, I cannot provide an exact answer. However, I can help you with the concept.
When rotating a point 90° counter clock-wise, the following happens: coordinates of the original point: (x,y) coordinates of the image point: (-y,x)
Examples: point (2,5) when rotated 90° counter clock-wise, the coordinates of the image would be (-5,2)
point (1,9) when rotated 90° counter clock-wise, the coordinates of the image would be (-9,1)
point (7,4) when rotated 90° counter clock-wise, the coordinates of the image would be (-4,7)
Therefore, for the given point Q, all you have to do to get the coordinates of the image is apply the transformation: (x,y) .............> are changed into.............> (-y,x)