You may also like

Tea Cups

Place the 16 different combinations of cup/saucer in this 4 by 4 arrangement so that no row or column contains more than one cup or saucer of the same colour.

Teddy Town

There are nine teddies in Teddy Town - three red, three blue and three yellow. There are also nine houses, three of each colour. Can you put them on the map of Teddy Town according to the rules?

Even Up

Consider all of the five digit numbers which we can form using only the digits 2, 4, 6 and 8. If these numbers are arranged in ascending order, what is the 512th number?


Age 11 to 14 Challenge Level:

A man has 5 coins in his pocket.

  • He can make 13 different amounts of money with his coins
  • The amounts of money he can make end with one of two possible digits.
  • He cannot make up exactly 70 pence
  • He cannot afford an item costing 1 pound
  • He can make a prime number bigger than 10 with his coins.

Given these clues, can you work out what the coins are?
Is there only one possible combination of coins?


Remove one of the clues. Are there any new possibilities for the values of the 5 coins?
Replace that clue and remove a different one, work out the new possibilities. Repeat for the other clues.

Can you remove a clue and only end up with your original solution(s)?

Which clues have the biggest impact?

Click here for a poster of this problem.