White shapes and black shapes are used in a game. Some of the shapes are circles.
All the other shapes are squares.
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The ratio of the number of white shapes to the number of black shapes is 5:11
The ratio of the number of white circles to the number of white squares is 3:7
The ratio of the number of black circles to the number of black squares is 3:8
Work out what fraction of all the shapes are circles.