Tree diagrams

problem
Same number!

Age

14 to 16

Challenge level

If everyone in your class picked a number from 1 to 225, do you think any two people would pick the same number?
problem
Succession in Randomia

Age

16 to 18

Challenge level

By tossing a coin one of three princes is chosen to be the next King of Randomia. Does each prince have an equal chance of taking the throne?
problem
Interactive spinners

Age

11 to 14

Challenge level

This interactivity invites you to make conjectures and explore probabilities of outcomes related to two independent events.
problem
Odds and evens

Age

11 to 14

Challenge level

Are these games fair? How can you tell?
problem
Flippin' discs

Age

11 to 14

Challenge level

Discs are flipped in the air. You win if all the faces show the same colour. What is the probability of winning?
problem
Chances are

Age

14 to 16

Challenge level

Which of these games would you play to give yourself the best possible chance of winning a prize?
problem
In a box

Age

14 to 16

Challenge level

Chris and Jo put two red and four blue ribbons in a box. They each pick a ribbon from the box without looking. Jo wins if the two ribbons are the same colour. Is the game fair?
problem
Master minding

Age

11 to 14

Challenge level

Your partner chooses two beads and places them side by side behind a screen. What is the minimum number of guesses you would need to be sure of guessing the two beads and their positions?
problem
Squash

Age

16 to 18

Challenge level

If the score is 8-8 do I have more chance of winning if the winner is the first to reach 9 points or the first to reach 10 points?
problem
Rain or shine

Age

16 to 18

Challenge level

Predict future weather using the probability that tomorrow is wet given today is wet and the probability that tomorrow is wet given that today is dry.