There are only green pens, black pens and red pens in a box.
There are four times as many green pens as black pens.
There are twice as many red pens as green pens.
Write down the ratio of green pens to black pens to red pens.
64 exam-style questions on Edexcel GCSE Maths Writing and Simplifying Ratio. Each one has a worked solution and a mark scheme showing where the marks go.