There are 3 red counters and x x\,x blue counters in a bag.
2 counters are removed from the bag at random.
The probability that both the counters taken are blue is 512\displaystyle \frac{5}{12}125.
Work out the value of xxx.
Practise OCR GCSE Maths Probability Equation Questions with exam-style questions for Foundation and Higher tier. 28 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.