Write the probability of a surve event.

Answer

To find the probability of a sure event, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Range of Probability**:
- Probability values range from 0 to 1. This means that the lowest probability (0) indicates an impossible event, while the highest probability (1) indicates a sure event.

2. **Define a Sure Event**:
- A sure event is an event that is guaranteed to happen. For example, if you flip a coin, the event of getting either heads or tails is a sure event (since one of them must occur).

3. **Identify the Probability of a Sure Event**:
- Since a sure event will definitely occur, its probability is represented by the value 1.

4. **Conclusion**:
- Therefore, the probability of a sure event is 1.

### Final Answer:
The probability of a sure event is **1**.

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