# Video: Determining the Probability of an Event in a Dice Experiment

What is the probability of rolling a number greater than 5 on a fair die?

02:16

### Video Transcript

What is the probability of rolling a number greater than five on a fair die?

First, let’s define probability. The probability of an event happening is equal to the number of ways that event can happen over the total number of outcomes. Our event is rolling a number greater than five. The numerator would be the numbers greater than five on a die and the denominator would be how many different numbers are on a die — what could you roll.

Here, we have a fair-sided die. The die has six different faces: a one, a two, a three, a four, a five, and a six. We now need to see how many of these faces are greater than five. On a regular fair-sided die, only one of the faces is greater than five and that’s the six. For a probability that makes the numerator one, there’s only one way to roll a number greater than five on a fair die.

And for the denominator, how many different numbers are there? What could we roll? Because a fair die has six different faces, there are six possible outcomes. And that means the probability of rolling a number greater than five on a fair die is one out of six. It’s only one of the options out of six total options.

The probability of rolling a number greater than five on a fair die one-sixth.