There are 4 green marbles and x x\,x yellow marbles in a bag.
2 marbles are removed from the bag at random.
The probability that both marbles taken are green is 215\displaystyle \frac{2}{15}152.
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.