mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

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 this puzzle, check out Sunday Afternoon Maths I,
puzzles about time, or a random puzzle.

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2023

Advent calendar 2022

Advent calendar 2021

Advent calendar 2020


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2024