There are 6 black pens and x x\,x blue pens in a drawer.
2 pens are taken from the drawer at random.
The probability that both pens taken are black is 13\displaystyle \frac{1}{3}31.
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.