Thank you to Anna from Mt Eliza North Primary School, Australia, who sent us this solution:
1. What are the possible results if 2 goals are scored in total?
2-0, 0-2, 1-1.
2. Why are they not all equally likely?
They are not all equally likely because there are two ways you can get the end result, 1-1, by the teachers scoring first and then the students or the students scoring first and then the teachers. There is one way for the end result, 2-0, the teachers get the 2 goals without the students getting 1. And there is only one way you can get the end result 0-2, by the students getting both the goals.
Therefore the end result 1-1 is more likely.
3. Is this a reasonable assumption?
Yes. Even if the teachers are more confident and the students are trying harder, those equal out so the chance would stay at 50-50.
4. What are the probabilities of each result according to Alison's model?
In Alison's model the team who scores first is twice as likely to score the next goal.
The chance of ending 2-0, with the teachers winning, is: