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?
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?
Move your counters through this snake of cards and see how far you
can go. Are you surprised by where you end up?
Engage in a little mathematical detective work to see if you can spot the fakes.
Can you work out the probability of winning the Mathsland National Lottery? Try our simulator to test out your ideas.
Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?
If everyone in your class picked a number from 1 to 225, do you
think any two people would pick the same number?
The NRICH Stage 5 weekly challenges are shorter problems aimed at Post-16 students or enthusiastic younger students. There are 52 of them.
We received a variety of good strategies for solving this problem.
Go to last month's problems to see more solutions.
Uncertain about the likelihood of unexpected events? You are not
This article explains how tree diagrams are constructed and helps
you to understand how they can be used to calculate probabilities.
Use this animation to experiment with lotteries. Choose how many
balls to match, how many are in the carousel, and how many draws to
make at once.
All you need for this game is a pack of cards. While you play the
game, think about strategies that will increase your chances of