mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

19 December

Today's number is the number of 6-dimensional sides on a 8-dimensional hypercube.

Show answer

Tags: 3d shapes

Cube multiples

Six different (strictly) positive integers are written on the faces of a cube. The sum of the numbers on any two adjacent faces is a multiple of 6.
What is the smallest possible sum of the six numbers?

Show answer & extension

3 December

What is the volume of the smallest cube inside which a rectangular-based pyramid of volume 266 will fit?

21 December

This year, I posted instructions for making a dodecahedron and a stellated rhombicuboctahedron.
To get today's number, multiply the number of modules needed to make a dodecahedron by half the number of tube maps used to make a stellated rhombicuboctahedron.

Show answer

2009

2009 unit cubes are glued together to form a cuboid. A pack, containing 2009 stickers, is opened, and there are enough stickers to place 1 sticker on each exposed face of each unit cube.
How many stickers from the pack are left?

Show answer & extension

Folding tube maps

Back in 2012, I posted instructions for folding a tetrahedron from tube maps. When tube maps are used, the sides of the tetrahedron are not quite equal. What ratio would the rectangular maps need to be in to give a regular tetrahedron?

Show answer & extension

Colliding parallel people

If two people stand 1km apart and walk in the same direction, how far will the have to walk until they collide due to the curvature of the Earth? (diameter of Earth = 12,742km)

Show answer & extension

Pyramid and tetrahedron

Source: MathsJam
If four equal equilateral triangles form the sides of a square-based pyramid, what is the ratio of the volume of the pyramid to the volume of the tetrahedron whose sides are the four triangles?

Show answer & extension

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2020

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018


List of all puzzles

Tags

sum to infinity calculus dodecagons hexagons range digital clocks digits crosswords numbers square numbers arrows coins median integers polygons shapes perimeter 3d shapes sums number the only crossnumber time gerrymandering ellipses unit fractions averages dominos dice people maths probability speed crossnumber money odd numbers christmas trigonometry doubling quadrilaterals squares books crossnumbers cards irreducible numbers coordinates cryptic crossnumbers area algebra perfect numbers cube numbers means indices folding tube maps rugby multiples differentiation partitions factors symmetry ave 2d shapes triangle numbers chocolate floors remainders fractions mean advent planes quadratics taxicab geometry products addition triangles parabolas complex numbers pascal's triangle circles logic regular shapes sequences sport chalkdust crossnumber spheres wordplay clocks grids geometry integration chess surds lines scales functions prime numbers star numbers rectangles cryptic clues palindromes percentages bases games combinatorics shape balancing tiling square roots menace colouring graphs volume routes angles division proportion elections factorials probabilty dates multiplication

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2021