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.