Combinations

There are 149 NRICH Mathematical resources connected to Combinations
Wag Worms
problem

Wag Worms

Age
7 to 11
Challenge level
filled star filled star filled star
When intergalactic Wag Worms are born they look just like a cube. Each year they grow another cube in any direction. Find all the shapes that five-year-old Wag Worms can be.
Waiting for Blast Off
problem

Waiting for Blast Off

Age
7 to 11
Challenge level
filled star filled star filled star
10 space travellers are waiting to board their spaceships. There are two rows of seats in the waiting room. Using the rules, where are they all sitting? Can you find all the possible ways?
A Rod and a Pole
problem

A Rod and a Pole

Age
7 to 11
Challenge level
filled star filled star empty star
A lady has a steel rod and a wooden pole and she knows the length of each. How can she measure out an 8 unit piece of pole?
Map Folding
problem

Map Folding

Age
7 to 11
Challenge level
filled star filled star empty star
Take a rectangle of paper and fold it in half, and half again, to make four smaller rectangles. How many different ways can you fold it up?
Calendar Cubes
problem

Calendar Cubes

Age
7 to 11
Challenge level
filled star filled star filled star
Make a pair of cubes that can be moved to show all the days of the month from the 1st to the 31st.
Team Scream
problem

Team Scream

Age
7 to 11
Challenge level
filled star filled star empty star
Seven friends went to a fun fair with lots of scary rides. They decided to pair up for rides until each friend had ridden once with each of the others. What was the total number rides?
Zargon Glasses
problem

Zargon Glasses

Age
7 to 11
Challenge level
filled star filled star empty star
Zumf makes spectacles for the residents of the planet Zargon, who have either 3 eyes or 4 eyes. How many lenses will Zumf need to make all the different orders for 9 families?
Octa Space
problem

Octa Space

Age
7 to 11
Challenge level
filled star filled star filled star
In the planet system of Octa the planets are arranged in the shape of an octahedron. How many different routes could be taken to get from Planet A to Planet Zargon?
Prison Cells
problem

Prison Cells

Age
7 to 11
Challenge level
filled star filled star empty star
There are 78 prisoners in a square cell block of twelve cells. The clever prison warder arranged them so there were 25 along each wall of the prison block. How did he do it?
Briefcase Lock
problem

Briefcase Lock

Age
5 to 7
Challenge level
filled star filled star empty star
My briefcase has a three-number combination lock, but I have forgotten the combination. I remember that there's a 3, a 5 and an 8. How many possible combinations are there to try?