6F: Compound Probability

Question

Gustavo is conducting an experiment in which he will roll a twelve-sided die, numbered 1 to 12, record its result, and then spin the spinner shown below.

What is the probability that the result of the roll and the spin is a two followed by an odd number?

Answer 1

First, consider the probability of landing a 2. Since the die has 12 options and each is equally likely, this is just 1/12.

Then consider the probability of landing an odd number on the spin. Since half the values are odd (1 and 3, but not 2 and 4) this is just 1/2.

Lastly, it's asking for the probability that BOTH of these things happen. This requires simply multiplying our answers, so our final answer is 1/12 * 1/2 = 1/24.