Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?
A circle touches the lines OA, OB and AB where OA and OB are perpendicular. Show that the diameter of the circle is equal to the perimeter of the triangle
Can you make a tetrahedron whose faces all have the same perimeter?
Each edge of a cube is coloured either red or black. If every face of the cube has at least one black edge, what is the smallest possible number of black edges?
This problem is taken from the UKMT Mathematical Challenges.View the archive of all weekly problems grouped by curriculum topic