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?
Imagine a room full of people who keep flipping coins until they
get a tail. Will anyone get six heads in a row?
Can you work out the probability of winning the Mathsland National Lottery? Try our simulator to test out your ideas.
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.
Mathmo is a revision tool for post-16 mathematics. It's great installed as a smartphone app, but it works well in pads and desktops and notebooks too. Give yourself a mathematical workout!
10 starting points for risk vs reward
Invent a set of three dice where each one is better than one of the others?
Explore these X-dice with numbers other than 1 to 6 on their faces.
Which one is best?
Calculate probabilities associated with the Derren Brown coin scam
in which he flipped 10 heads in a row.
Lots of you noticed interesting patterns in the spreadsheet, and
some went on to explain the patterns using algebra.
Go to last month's problems to see more solutions.
Uncertain about the likelihood of unexpected events? You are not
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