Leon created a scale drawing of the school library in his art class in the scale drawing the length of the library is 13 inches the actual length is 78 feet which scale did Leon use to creat the scale drawing of the school library

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.