Question

Suppose you roll a special 9-sided die. What is the probability that the number rolled is a "1" OR a "2"?

Answer 1

P(1 or 2) = 2/9

Explanation:

OR means we add each probability

If it is 9-sided, I will assume the die will be numbered 1-9

Probability of getting a 1 in mathematical notation is:

P(1) = 1/9

Probability of getting 2:

P(2) = 1/9

We add their probabilities since we want to know if we get either 1 or 2

P(1) + P(2) = 1/9 + 1/9 = 2/9

If the question asked what the probability was of getting a 1 and a 2 by rolling the die twice, we would multiply the probabilities together

1/9 x 1/9 = 1/81