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Nine or Ten?

Is a score of 9 more likely than a score of 10 when you roll three dice?

Racing Odds

In a race the odds are: 2 to 1 against the rhinoceros winning and 3 to 2 against the hippopotamus winning. What are the odds against the elephant winning if the race is fair?

Stop or Dare

All you need for this game is a pack of cards. While you play the game, think about strategies that will increase your chances of winning.

Strange Dice

Age 11 to 14 Short Challenge Level:

An unusual die has its six faces labelled 1, 2, 3, 5, 7, 9.

If two such dice are rolled, and the numbers rolled added together, then how many different sums are possible?

Can you say which sums are most likely?


This problem is adapted from the World Mathematics Championships
You can find more short problems, arranged by curriculum topic, in our short problems collection.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
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