Topics
15. Probability
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Stage 3

15.02 Outcomes

Lesson
Practice
Lesson

Are you ready?

Can you remember the words we can use to  describe chance  ?

Examples

Example 1

What is the chance of winning the lottery?

A
Impossible
B
Unlikely
Worked Solution
Create a strategy

Think about if it is possible to win the lottery.

Apply the idea

Winning the lottery does happen but it is extremely rare. So it is unlikely to win the lottery. So the answer is option B.

Idea summary

If an event is impossible, then it cannot happen.

If an event is unlikely, then it rarely happens or probably won't happen.

Spinners and dice

Do you know how to use and interpret the actions of a spinner or a die? This video will show you how.

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Examples

Example 2

If you spin this spinner:

A spinner with 3 apples, 2 pigs, 2 balls, and 1 star on it.
a

What is the most likely symbol to spin?

A
This image shows a pig.
B
This image shows a basketball.
C
This image shows an apple.
Worked Solution
Create a strategy

Count how many times each picture appears on the spinner.

Apply the idea

The apple symbol appears 3 times, the pig appears 2 times and the ball appears 2 times. The most likely symbol to spin is an apple since it appears the most.

The correct option is C.

b

What is the likelihood of spinning an apple?

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

Count the number of apples on the spinner and compare it to the total number of symbols that appear on the spinner.

Apply the idea

There is 3 apple symbols out of 8 symbols on the spinner. 3 out of 8 is not too many, since 3 is less than half of 8.

So it is unlikely to spin an apple. The correct answer is option A.

Idea summary

If something appears on a spinner or die more than half the time, then it will be likely to land on.

If something appears on a spinner or die less than half the time, then it will be unlikely to land on.

Cards

Playing cards are often used as a prop when exploring chance. This video will show you what is in a deck of cards so you can make sense of chance questions about cards.

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Examples

Example 3

These four cards are shuffled and you draw one at random:

Four playing cards. A 5 of Diamonds, a King of Hearts, a Queen of Spades, and a 3 of Clubs.
a

What are the chances of drawing a Jack, Queen, or King?

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

Count the number of cards that are either a King, Jack or Queen and compare it to the total number of cards present.

Apply the idea

There are 4 cards in total, and 2 of them are Jacks, Queens, or Kings. 2 out of 4 means it can happen half of the time or there is an even chance of happening. So the answer is option C.

b

What are the chances of drawing a card with a number less than 4?

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

Count the number of card that are less than 4 and compare it to the total number of cards present.

Apply the idea

There is 1 card out of 4 cards that is less than 4. 1 out of 4 is less than half so it is unlikely to draw a card that is less than 4.

The correct answer is option A.

Idea summary

Whatever we use to look at chance, it's important to consider all of the possible outcomes, as well as the total objects we have.

Outcomes

MA3-19SP

conducts chance experiments and assigns probabilities as values between 0 and 1 to describe their outcomes

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