Quadrilateral ABCD is transformed according to the rule (x, y) → (y, –x). Which is another way to state the transformation? R0, 90°
R0, 180°
R0, 270°
R0, 360°

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.