Skip to main content
### Number and algebra

### Geometry and measure

### Probability and statistics

### Working mathematically

### For younger learners

### Advanced mathematics

# Coin Collection

## You may also like

### Novemberish

Or search by topic

Age 14 to 16

ShortChallenge Level

- Problem
- Solutions

Tom has a collection of more than $24$ coins. When he puts the coins in piles of $6$, there are $3$ coins remaining. When he puts the coins in piles of $8$, there are $7$ coins remaining. How many coins remain when he puts the coins in piles of $24$?

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.

This problem is taken from the UKMT Mathematical Challenges.

You can find more short problems, arranged by curriculum topic, in our short problems collection.

a) A four digit number (in base 10) aabb is a perfect square. Discuss ways of systematically finding this number. (b) Prove that 11^{10}-1 is divisible by 100.