problem
Favourite
Two's company
Age
11 to 14
Challenge level
Seven balls are shaken. You win if the two blue balls end up touching. What is the probability of winning?
problem
Favourite
Cosy corner
Age
11 to 14
Challenge level
Six balls are shaken. You win if at least one red ball ends in a corner. What is the probability of winning?
problem
Favourite
Litov's mean value theorem
Age
11 to 14
Challenge level
Start with two numbers and generate a sequence where the next number is the mean of the last two numbers...
problem
Favourite
Which spinners?
Age
14 to 18
Challenge level
Can you work out which spinners were used to generate the frequency charts?
problem
Favourite
Searching for mean(ing)
Age
11 to 16
Challenge level
If you have a large supply of 3kg and 8kg weights, how many of each would you need for the average (mean) of the weights to be 6kg?
problem
Favourite
Last one standing
Age
14 to 16
Challenge level
Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?
problem
Favourite
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
Favourite
Mathsland national lottery
Age
14 to 16
Challenge level
Can you work out the probability of winning the Mathsland National Lottery?
problem
Favourite
Who's the best?
Age
11 to 14
Challenge level
Which countries have the most naturally athletic populations?
problem
Favourite
Non-transitive dice
Age
11 to 14
Challenge level
Alison and Charlie are playing a game. Charlie wants to go first so Alison lets him. Was that such a good idea?
problem
Favourite
Odds and evens made fair
Age
14 to 16
Challenge level
In this follow-up to the problem Odds and Evens, we invite you to analyse a probability situation in order to find the general solution for a fair game.
problem
Favourite
Estimating time
Age
11 to 14
Challenge level
How well can you estimate 10 seconds? Investigate with our timing tool.
problem
Favourite
Wipeout
Age
11 to 16
Challenge level
Can you do a little mathematical detective work to figure out which number has been wiped out?
problem
Favourite
Unequal averages
Age
11 to 14
Challenge level
Play around with sets of five numbers and see what you can discover about different types of average...