Why does say its answers are correct yet I have spotted several of there answer's that are wrong. This is why i am very meticulous on what sites i use to study for my exams. My advice for anyone looking to study for exams would be not to come here.

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.