Explanation

A Venn diagram visually shows relationships between sets.

Addition Rule for Probability:
P(A ∪ B) = P(A) + P(B) − P(A ∩ B)

• P(A ∪ B): probability of A or B occurring

• P(A ∩ B): probability of both A and B occurring

Example:

• 30% like apples (A)

• 25% like bananas (B)

• 10% like both

P(A ∪ B) = 0.30 + 0.25 − 0.10 = 0.45

Quiz

1. What does a Venn diagram show?

2. Write the addition rule formula.

3. What does P(A ∩ B) represent?

4. Calculate P(A ∪ B) if P(A) = 0.6, P(B) = 0.4, P(A ∩ B) = 0.2.

5. Can events be mutually exclusive in the addition rule?

Answer Key

1. Relationships between sets

2. P(A ∪ B) = P(A) + P(B) − P(A ∩ B)

3. Probability of both events occurring

4. 0.6 + 0.4 − 0.2 = 0.8

5. Yes