A gardener is mixing plant food by combining nitrogen (x x\,x g) and potash (y y\,y g) in the ratio 9:109:109:10.
Use this information to draw a graph showing the relationship between the amount of nitrogen and the amount of potash used.
The gardener decides to use 55 g of potash. Use your graph to work out how much nitrogen he should use.
60 exam-style questions on Edexcel GCSE Maths Writing a Ratio as a Fraction or Linear Function. Each one has a worked solution and a mark scheme showing where the marks go.