You may also like

problem icon

Just Rolling Round

P is a point on the circumference of a circle radius r which rolls, without slipping, inside a circle of radius 2r. What is the locus of P?

problem icon

Coke Machine

The coke machine in college takes 50 pence pieces. It also takes a certain foreign coin of traditional design...

problem icon

Rotating Triangle

What happens to the perimeter of triangle ABC as the two smaller circles change size and roll around inside the bigger circle?


Stage: 4 Challenge Level: Challenge Level:2 Challenge Level:2

9 identical squares of side 2 units are separated by empty strips also of 2 units width.

What is the shortest route from A to B, assuming you can only go around the edges of the squares?

Now, consider 27 identical cubes of side 2 units which are separated by corridors also of 2 units width. What is the shortest distance from A to B?