Probability - Stage 3

In a Box

Stage: 3 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?

Flippin' Discs

Stage: 3 Challenge Level:

Identical discs are flipped in the air. You win if all of the faces show the same colour. Can you calculate the probability of winning with n discs?

Odds and Evens

Stage: 3 and 4 Challenge Level:

Is this a fair game? How many ways are there of creating a fair game by adding odd and even numbers?

Two's Company

Stage: 3 Challenge Level:

7 balls are shaken in a container. You win if the two blue balls touch. What is the probability of winning?

Cosy Corner

Stage: 3 Challenge Level:

Six balls of various colours are randomly shaken into a trianglular arrangement. What is the probability of having at least one red in the corner?

Interactive Spinners

Stage: 3 and 4 Challenge Level:

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

Sociable Cards

Stage: 3 Challenge Level:

Move your counters through this snake of cards and see how far you can go. Are you surprised by where you end up?

Do You Feel Lucky?

Stage: 3 and 4 Challenge Level:

Some people offer advice on how to win at games of chance, or how to influence probability in your favour. Can you decide whether advice is good or not?

What Does Random Look Like?

Stage: 3 Challenge Level:

Engage in a little mathematical detective work to see if you can spot the fakes.

At Least One...

Stage: 3 and 4 Challenge Level:

Imagine flipping a coin a number of times. Can you work out the probability you will get a head on at least one of the flips?

Non-transitive Dice

Stage: 3 and 4 Challenge Level:

Alison and Charlie are playing a game. Charlie wants to go first so Alison lets him. Was that such a good idea?

Short Problems

Stage: 3 Challenge Level:

A collection of short Stage 3 problems on probability.