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### Number and algebra

### Geometry and measure

### Probability and statistics

### Working mathematically

### For younger learners

### Advanced mathematics

# Two's Company

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### Master Minding

### Flippin' Discs

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Links to the University of Cambridge website
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Nurturing young mathematicians: teacher webinars

30 April (Primary), 1 May (Secondary)

30 April (Primary), 1 May (Secondary)

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Age 11 to 14

Challenge Level

*Two's Company printable sheet - problem*

*Two's Company printable sheet - recording sheets*

A container holds $4$ yellow marbles, $2$ blue marbles and $1$ red marble.

The marbles are identical in all ways except colour.

Run the interactivity below to simulate shaking the container.

**You win if two blue marbles touch.**

Did you win?

Complete several shakes and look at your results.

Approximately how often do you think you would win if you completed $100$ throws?

Make a prediction and then check it by doing the experiment.

Can you find a way of working out the theoretical probability of winning?

You may find these Recording Sheets useful.

Your partner chooses two beads and places them side by side behind a screen. What is the minimum number of guesses you would need to be sure of guessing the two beads and their positions?

Discs are flipped in the air. You win if all the faces show the same colour. What is the probability of winning?

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