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.
28 exam-style questions on Edexcel GCSE Maths Probability Equation Questions. Each one has a worked solution and a mark scheme showing where the marks go.