There are some counters in a box.
15\displaystyle \frac{1}{5}51 of the counters are red.
The rest of the counters are blue.
Write the ratio of the number of red counters to the number of blue counters.
Give your answer in the form 1:n1 : n1:n
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.