
problem
Two's company
Seven balls are shaken. You win if the two blue balls end up touching. What is the probability of winning?

problem
Cosy corner
Six balls are shaken. You win if at least one red ball ends in a corner. What is the probability of winning?

problem
Litov's mean value theorem
Start with two numbers and generate a sequence where the next number is the mean of the last two numbers...


problem
Searching for mean(ing)
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
Last one standing
Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?

problem
Same number!
If everyone in your class picked a number from 1 to 225, do you think any two people would pick the same number?

problem
Mathsland national lottery
Can you work out the probability of winning the Mathsland National Lottery?


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

problem
Odds and evens made fair
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
Unequal averages
Play around with sets of five numbers and see what you can discover about different types of average...

problem
Wipeout
Can you do a little mathematical detective work to figure out which number has been wiped out?