Which of the following relations is a function? a.{ (-2, 4), (-1, 3), (5, 2), (1, 4) } b.{ (1, 7), (1, 8), (2, 7), (3, 8) } c.{ (2, 4), (4, 6), (4, 8), (6, 4) } d.{ (5, 7), (6, 3), (8, 6), (5, 4) }

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.