Combinations

There are 149 NRICH Mathematical resources connected to Combinations
A City of Towers
problem

A City of Towers

Age
5 to 7
Challenge level
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In this town, houses are built with one room for each person. There are some families of seven people living in the town. In how many different ways can they build their houses?
Three Way Mix Up
problem

Three Way Mix Up

Age
5 to 11
Challenge level
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Jack has nine tiles. He put them together to make a square so that two tiles of the same colour were not beside each other. Can you find another way to do it?
Jumping Cricket
problem

Jumping Cricket

Age
5 to 7
Challenge level
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El Crico the cricket has to cross a square patio to get home. He can jump the length of one tile, two tiles and three tiles. Can you find a path that would get El Crico home in three jumps?
Mixed-up Socks
problem

Mixed-up Socks

Age
5 to 7
Challenge level
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Start with three pairs of socks. Now mix them up so that no mismatched pair is the same as another mismatched pair. Is there more than one way to do it?
Three by Three
problem

Three by Three

Age
5 to 11
Challenge level
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Arrange 3 red, 3 blue and 3 yellow counters into a three-by-three square grid, so that there is only one of each colour in every row and every column
Snakes
problem

Snakes

Age
5 to 7
Challenge level
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Explore the different snakes that can be made using 5 cubes.
Two Dice
problem

Two Dice

Age
5 to 7
Challenge level
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Find all the numbers that can be made by adding the dots on two dice.
Red Express Train
problem

Red Express Train

Age
5 to 7
Challenge level
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The Red Express Train usually has five red carriages. How many ways can you find to add two blue carriages?
Five Coins
problem

Five Coins

Age
5 to 11
Challenge level
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Ben has five coins in his pocket. How much money might he have?
3 blocks towers
problem

Three block towers

Age
5 to 7
Challenge level
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Take three differently coloured blocks - maybe red, yellow and blue. Make a tower using one of each colour. How many different towers can you make?