You may also like

Building Tetrahedra

Can you make a tetrahedron whose faces all have the same perimeter?

Ladder and Cube

A 1 metre cube has one face on the ground and one face against a wall. A 4 metre ladder leans against the wall and just touches the cube. How high is the top of the ladder above the ground?

Bendy Quad

Four rods are hinged at their ends to form a convex quadrilateral. Investigate the different shapes that the quadrilateral can take. Be patient this problem may be slow to load.

Threes and Fours

Age 14 to 16 Short
Challenge Level

Answer: 3444

Digits add up to a multiple of 3
3 + 4 = 7 (at least one of each)
Adding more 3s will not help get closer to a multiple of 3
3 + 4 + 4 = 11
3 + 4 + 4 + 4 = 15

Smallest possibility: 3444
44 is divisible by 4 so 3444 is divisible by 4

This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.