There are some red counters and some blue counters in a bag.
The ratio of red counters to blue counters is 4:1.
Two counters are removed at random.
The probability that both the counters taken are red is 2235\displaystyle \frac{22}{35}3522
Work how many blue counters are in the bag.
7 exam-style questions on Edexcel IGCSE Maths Probability Equation Questions. Each one has a worked solution and a mark scheme showing where the marks go.