If A and B are such that `P(A'cupB')=2/3andP(AcupB)=5/9` then P(A')+P(B') is equal to …….. .

Explanation

To solve the problem, we need to find \( P(A') + P(B') \) given that \( P(A' \cup B') = \frac{2}{3} \) and \( P(A \cup B) = \frac{5}{9} \).

### Step-by-step Solution:

1. **Understanding the Complement Rule**:
We know that:
\[
P(A') = 1 - P(A) \quad \text{and} \quad P(B') = 1 - P(B)
...