mscroggs.co.uk
mscroggs.co.uk

subscribe

Sunday Afternoon Maths I

 Posted on 2014-02-23 

8! minutes

How many weeks are there in 8! (\(8\times 7\times 6\times 5\times 4\times 3\times 2\times 1\)) minutes?

Show answer & extension

Tags: numbers, time

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

Circles

Source: MathsJam
There is a quarter circle with radius 2r and centre A and two semi circles with radius r and centres B and C.
Prove that the red area is equal to the blue area.

Show answer & extension

Pole position

Two poles stand vertically on level ground. One is 10 feet tall, the other 15 feet tall. If a line is drawn from the top of each pole to the bottom of the other, the two lines intersect at a point 6 feet above the ground. What's the distance between the poles?

Show answer & extension

Burning ropes

You have two ropes and some matches. Each rope, if lit at its end, will burn for 60 minutes. But the rate of burning is not regular, so cutting a rope in half doesn't result in a burn time of 30 minutes.
How can you use the ropes to time exactly 45 minutes?

Show answer & extension

Tags: time
If you enjoyed these puzzles, check out Advent calendar 2024,
puzzles about combinatorics, or a random puzzle.

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2024

Advent calendar 2023

Advent calendar 2022

Advent calendar 2021


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2025