If the probability of an event to occur is 55% , then what is the probability on non occurrence of that event .

Answer

To find the probability of the non-occurrence of an event when the probability of the event occurring is given, follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Probability**:
- The probability of the event occurring is given as 55%. This can be expressed as a decimal:
\[ P(A) = 55\% = \frac{55}{100} = 0.55 \]

2. **Use the Complement Rule**:
- The probability of the non-occurrence of the event (denoted as \( P(A') \)) can be found using the complement rule:
\[ P(A') = 1 - P(A) \]

3. **Substitute the Value**:
- Substitute the value of \( P(A) \) into the equation:
\[ P(A') = 1 - 0.55 \]

4. **Perform the Calculation**:
- Now, calculate the result:
\[ P(A') = 1 - 0.55 = 0.45 \]

5. **Convert Back to Percentage**:
- To express the probability of non-occurrence as a percentage:
\[ P(A') = 0.45 \times 100 = 45\% \]

### Final Answer:
The probability of the non-occurrence of the event is **45%**.

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