2.7 Tree Diagrams
1. Students have to pass an exam to gain a certificate. The probability of passing the exam at the first attempt is 0.70. Those who fail are allowed to re-sit. The probability of passing the re-sit is 0.6. No further attempts are allowed.
Draw a tree diagram of this situation.
2. What is the probability failing followed by passing?
Using the AND rule for calculating conditional probabilities:
3. What is the probability failing twice?
Using the AND rule for calculating conditional probabilities:
Tree Diagrams
The sum of the outcomes for each event must be equal to 1.
