GCSE Secondary Maths Age 13-17 - Probability & Statistics: Probability - Explained

The video tutorial explains the probability of a car being stopped by two sets of traffic lights, A and B, using a tree diagram. It details the steps to complete the diagram, ensuring all branches add up to one. The tutorial then calculates the probability of Mark being stopped by only one set of lights, concluding that it is more likely he was stopped by lights B. The video also discusses the allocation of marks for solving the problem, emphasizing the importance of understanding tree diagrams and probability calculations.

What must all branches of a probability tree diagram add up to?

What is the probability that Mark was stopped by lightspeed?

Is it more likely that Mark was stopped by lights A or by lightspeed? Explain your reasoning.