1. **Problem Statement:** What is the probability of an impossible event? 2. **Understanding Probability:** The probability of any event is given by the formula: $$P(E) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$$ 3. **Important Rule:** - The probability of an impossible event is always 0 because there are no favorable outcomes. - Probability values always lie between 0 and 1 inclusive. 4. **Applying the Rule:** Since an impossible event cannot occur, the number of favorable outcomes is 0. Therefore, $$P(\text{impossible event}) = 0$$ 5. **Answer:** The probability of an impossible event is 0. Hence, the correct choice is (b) 0.