Skip to main content
### Number and algebra

### Geometry and measure

### Probability and statistics

### Working mathematically

### For younger learners

### Advanced mathematics

# At Least One...

If there isn't at least one head, what must be true about every flip of the coin?

## You may also like

### Master Minding

### Flippin' Discs

Or search by topic

Age 11 to 14

Challenge Level

- Problem
- Getting Started
- Student Solutions
- Teachers' Resources

If there isn't at least one head, what must be true about every flip of the coin?

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?