List possible outcomes
Theory
Listing the possible outcomes is a Year 3 chance skill: naming every different result of a simple chance experiment and counting them. This page covers the outcomes of a coin (heads or tails), a die (1 to 6), a colour spinner, letter cards and drawing a counter from a bag, and how to tell whether the outcomes are equally likely. Curriculum: VC2M3P01 / AC9M3P01.
A chance experiment is something with a result you cannot be sure of before it happens, like tossing a coin or rolling a die. An outcome is one result that could happen.
The possible outcomes are all the different results you could get. To find them, name each one, then count how many there are. A coin can land on heads or tails, so it has \(2\) outcomes. A standard die can show \(1, 2, 3, 4, 5\) or \(6\), so it has \(6\) outcomes.
For a spinner or a bag, there is one outcome for each different colour. Count the different results, not the objects: a bag of \(4\) green and \(2\) yellow counters still has only \(2\) colour outcomes. Outcomes are equally likely when each one has the same chance, such as the equal parts of a fair spinner.
Listing outcomes does not need formulas, but these common counts are worth remembering.
| Experiment | Possible outcomes | How many |
|---|---|---|
| Toss a coin | heads, tails | 2 |
| Roll a die | 1, 2, 3, 4, 5, 6 | 6 |
| Spinner with 3 colours | one per colour | 3 |
| Spinner with 5 colours | one per colour | 5 |
| Cards with different letters | one per letter | one per card |
How to list all the possible outcomes
- Name the experiment. Work out what is happening: a coin toss, a die roll, a spin, a card or a draw from a bag.
- List each result. Write down every different thing that could happen, one at a time, and do not repeat any.
- Count them. Count how many results you listed. That number is how many possible outcomes there are.
- Check if they are equally likely. Equal parts or equal counts mean equally likely. A bigger part or more counters makes that outcome more likely.
The counter lands on one of its two sides.
| \(\text{outcomes}\) | \(=\) | \(\text{red, yellow}\) |
| \(\text{count}\) | \(=\) | \(2\) |
There are \(2\) possible outcomes. A coin works the same way: it has two faces.
Write each number the cube can show.
| \(\text{outcomes}\) | \(=\) | \(2, 4, 6, 8, 10, 12\) |
| \(\text{count}\) | \(=\) | \(6\) |
There are \(6\) possible outcomes. The smallest is \(2\) and the largest is \(12\), so a number such as \(5\) or \(20\) can never be rolled. A standard die works the same way, with the numbers \(1\) to \(6\).
The arrow can stop on each colour.
| \(\text{outcomes}\) | \(=\) | \(\text{red, yellow, purple}\) |
| \(\text{count}\) | \(=\) | \(3\) |
There are \(3\) possible outcomes. The parts are equal, so the three colours are equally likely.
Count the different colours, not the counters.
| \(\text{outcomes}\) | \(=\) | \(\text{red, yellow}\) |
| \(\text{count}\) | \(=\) | \(2\) |
There are \(2\) colour outcomes.
| \(\text{outcomes}\) | \(=\) | \(\text{green, orange, purple}\) |
| \(\text{count}\) | \(=\) | \(3\) |
There are \(3\) outcomes, but they are not equally likely: the green part is bigger, so green is more likely than orange or purple.
| \(\text{outcomes}\) | \(=\) | \(\text{F, R, O, G}\) |
| \(\text{count}\) | \(=\) | \(4\) |
There are \(4\) possible outcomes, one for each different letter. Each card is equally likely to be picked.
Common pitfalls
Frequently asked questions
What are the possible outcomes of tossing a coin?
A coin can land on heads or tails. So there are two possible outcomes: heads and tails.
How many possible outcomes are there when you roll a standard die?
A standard six-sided die can show \(1, 2, 3, 4, 5\) or \(6\). That is six possible outcomes, and on a fair die they are all equally likely.
What is an outcome in maths?
An outcome is one result that could happen in a chance experiment. Tossing a coin has two outcomes, heads and tails.
How do you list all the possible outcomes?
Name every different result that could happen, one at a time, and then count how many you listed. For a colour spinner, list each colour the arrow can stop on.
Do you count the counters or the colours in a bag?
You count the different colours, not the counters. A bag with \(6\) green and \(1\) white counter has only two colour outcomes, green and white.
What does equally likely mean?
Equally likely means every outcome has the same chance. A spinner with equal parts in different colours gives every colour the same chance.