In a stationery shop, there are red, blue, and green pens. There are three times as many blue pens as red pens. There are 15 fewer green pens than blue pens. There are 195 pens in total.
Find the ratio of the number of red pens to blue pens to green pens.
Practise OCR GCSE Maths Forming and Solving Equations with exam-style questions for Foundation and Higher tier. 78 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.