A trial selects one block from a collection at each stage
The initial category counts, in the branch order shown, are round = 9, square = 5, flat = 6
At each stage, choose uniformly at random from the individual items currently in the container
The trial has 2 stages: stage 1 and stage 2. After each selection, the item is returned before the next stage
The ordered terminal outcomes form the sample space \(S\). Let \(E\) be the event that the ordered outcome is (square, flat)
If needed, scroll sideways to follow each complete path
Read stages from left to right. A ? marks a branch probability to calculate. Terminal labels show the complete ordered outcomes