Working systematically

problem

Two Egg Timers

Age

7 to 11

Challenge level

You have two egg timers. One takes 4 minutes exactly to empty and the other takes 7 minutes. What times in whole minutes can you measure and how?
problem

Home City

Age

7 to 11

Challenge level

Use the clues to work out which cities Mohamed, Sheng, Tanya and Bharat live in.
problem

Professional Circles

Age

7 to 11

Challenge level

Six friends sat around a circular table. Can you work out from the information who sat where and what their profession were?
problem

Dodecamagic

Age

7 to 11

Challenge level

Here you see the front and back views of a dodecahedron. Each vertex has been numbered so that the numbers around each pentagonal face add up to 65. Can you find all the missing numbers?
problem

A Right Charlie

Age

7 to 11

Challenge level

Can you use this information to work out Charlie's house number?
problem

Zargon Glasses

Age

7 to 11

Challenge level

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?
problem

Arranging the Tables

Age

7 to 11

Challenge level

There are 44 people coming to a dinner party. There are 15 square tables that seat 4 people. Find a way to seat the 44 people using all 15 tables, with no empty places.
problem

Team Scream

Age

7 to 11

Challenge level

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?
problem

Map Folding

Age

7 to 11

Challenge level

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?
problem

Creating Cubes

Age

7 to 11

Challenge level

Arrange 9 red cubes, 9 blue cubes and 9 yellow cubes into a large 3 by 3 cube. No row or column of cubes must contain two cubes of the same colour.