1. Definition
The union has P(A∪B)=P(A)+P(B)−P(AB); for disjoint events P(AB)=0.
3. Properties & Laws
- Subtract overlap to avoid double count;
- Disjoint P(AB)=0;
- Complement sums to 1;
- Result ≤1.
4. Steps
- Enter three probabilities;
- Click "Calculate";
- Or click "Load Example".
5. Worked Examples
Example: 0.6+0.5−0.3: 0.8.
6. Common Pitfalls
Subtract overlap;
Only add directly when disjoint;
Probability ≤1.