# 11.01 Describe likelihood

Lesson

## Ideas

What words can you think of that describe the the chance of something happening? Can you think of examples of events that fit each word you can think of?

### Examples

#### Example 1

What is the chance my paper plane will fly forever?

A
Impossible
B
In between certain and impossible
C
Certain
Worked Solution
Create a strategy

Think about if a paper plane can fly forever.

Apply the idea

A paper plane must eventually land so it is impossible that it will fly forever. The answer is option A.

Idea summary

These are the 2 terms we have seen to describe chance:

• Impossible: definitely will NOT happen.

• Certain: definitely will happen.

## Words to describe chance

This video shows us how to describe the likelihood of events.

### Examples

#### Example 2

What is the chance of flipping heads with a coin?

A
Unlikely
B
Likely
C
Even chance
Worked Solution
Create a strategy

Compare how often each outcome will happen.

Apply the idea

When flipping a coin, half the time it will land on heads and half the time it will land on tails.

Each side is equally likely to land face-up.

The correct option is C.

Idea summary

More terms to describe chance:

• Unlikely: more likely NOT to happen than to happen.

• Even chance: one thing is not more likely to happen than the other

• Likely: more likely to happen than not to happen.

## Order of chances

How likely something is can be visualised on a line similar to a number line. This video shows us how.

### Examples

#### Example 3

Which section describes the chance of 'the next person you meet has the same birthday as you'?

A
B
Worked Solution
Create a strategy

Think about how often you meet someone with the same birthday as you.

Apply the idea

It is unlikely that the next person you meet has the same birthday as you.

An unlikely event will have a chance between impossible and even chance, which is described by the purple section.

The correct option is A.

Idea summary

In order of how much chance something has of happening, we can start from the left, and move right. It's just like a number line.

### Outcomes

#### VCMSP175

Describe possible everyday events and order their chances of occurring