To calculate the probability of rolling a number divisible by 3 on a 12-sided die, we need to:

1. Determine the total possible outcomes: The die has 12 faces, so the total number of possible outcomes is 12.

2. Identify the favorable outcomes: Numbers divisible by 3 between 1 and 12 are: 3, 6, 9, and 12. So, there are 4 favorable outcomes.

3. Calculate the probability: $P(\text{Event A}) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \frac{4}{12} = \frac{1}{3}$

Therefore, the probability of rolling a number divisible by 3 is $\frac{1}{3}$.

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Related Questions:

1. How would the probability change if the die had 20 faces instead of 12?
2. What is the probability of rolling a number divisible by 2 or 3?
3. How can you express this probability as a percentage?
4. What is the probability of rolling a number greater than 10 on a 12-sided die?
5. How would the probability be affected if the die had only even-numbered faces?

Tip: When calculating probability, always simplify the fraction if possible.