problem

### Do you brush your teeth every day?

How can we find out answers to questions like this if people often lie?

problem
###
Do you brush your teeth every day?

How can we find out answers to questions like this if people often lie?

problem
###
At least one...

Favourite

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?

problem
###
Same Number!

Favourite

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

problem
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Molecular sequencer

Investigate the molecular masses in this sequence of molecules and deduce which molecule has been analysed in the mass spectrometer.

problem
###
Taking Chances

This article, for students and teachers, is mainly about
probability, the mathematical way of looking at random chance and
is a shorter version of Taking Chances Extended.

problem
###
The Better Choice

Favourite

Here are two games you can play. Which offers the better chance of winning?

problem
###
Put Out

Favourite

After transferring balls back and forth between two bags the
probability of selecting a green ball from bag 2 is 3/5. How many
green balls were in bag 2 at the outset?

problem
###
Voting Paradox

Some relationships are transitive, such as `if A>B and B>C
then it follows that A>C', but some are not. In a voting system,
if A beats B and B beats C should we expect A to beat C?