Compound events, the addition rule and mutual exclusivity
A synthetic classification records two properties for each folder
Event A: the folder is labelled. Event B: the folder is stored online
Let S be the sample space of all 40 recorded cases
The counts in the four disjoint regions are shown below
| Region | Count |
|---|---|
| A only | 13 |
| B only | 2 |
| A and B | 12 |
| Neither A nor B | 13 |
For the requested probability, select one recorded case uniformly at random