In a bag there are only red counters, blue counters, green counters and yellow counters. A counter is taken at random from the bag. The table shows the probabilities that the counter will be green or will be yellow.
| Colour | Red | Blue | Green | Yellow |
|---|---|---|---|---|
| Probability | 0.35 | 0.20 |
The probability that the counter will be red is twice the probability that the counter will be blue. There are 18 red counters in the bag.
Work out the number of green counters in the bag.
324 exam-style questions on AQA GCSE Maths Probability. Each one has a worked solution and a mark scheme showing where the marks go.