Write the ratio 12:30 12 : 30\,12:30 in its simplest form.
In a box of pens, 27\displaystyle \frac{2}{7}72 of the pens are black.
Write the ratio of the number of black pens to the number of pens that are not black.
Practise OCR GCSE Maths Writing and Simplifying Ratio with exam-style questions for Foundation and Higher tier. 64 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.